NetChoice, LLC v. Paxton

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Mark Timothy Pittman

Judge, United States District Court for the Northern District of Texas

Biography

Immediately preceding his appointment to the federal bench, Judge Pittman was an Associate Justice on the Court of Appeals for the Second District of Texas since 2017. Prior to his appointment to the Court of Appeals, he served for two years on the trial bench of the 352nd Judicial District Court in Tarrant County.

Judge Pittman is also an experienced litigator, having served as an Enforcement Attorney at the U.S. Securities and Exchange Commission, where he also spent a year on special assignment prosecuting economic crimes as a Special Assistant U.S. Attorney. Prior to that, he was a Senior Attorney for the Federal Deposit Insurance Corporation, an Assistant U.S. Attorney for the Northern District of Texas, and a Trial Attorney in the Civil Division of the U.S. Department of Justice in Washington, D.C. He has also worked in private practice as a civil litigation attorney with Kelly, Hart and Hallman, LLP and served as a law clerk to United States District Judge Eldon B. Mahon in the Northern District of Texas, Fort Worth Division.

Judge Pittman received a Bachelor of Arts degree magna cum laude from Texas A&M University in 1996, and a Doctor of Jurisprudence degree from the University of Texas School of Law in 1999. While studying law, he clerked in the General Counsel’s Office of the Governor of Texas under Governor George W. Bush and was a founding member of the Texas Review of Law & Politics.

Judge Pittman is a former vice-president and founding member of the Fort Worth Chapter of the Federalist Society and a master of the Eldon B. Mahon Inn of Court. He serves on the Board of Ballet Concerto of Fort Worth and the Tarrant County Volunteer Attorney Services Committee and coaches youth sports at the YMCA. Judge Pittman, a history buff, is a member of the Fort Worth Civil War Roundtable and the A.M. Pate Book Award in Civil War History selection committee. A sixth generation Texan, he was born in Big Spring and raised in Cooper. He and his wife, Katrina, have been married fifteen years and are the parents of four children.

Benjamin D. Wilson

Of Counsel, Gibson Dunn & Crutcher LLP

Biography

Benjamin D. Wilson is Of Counsel in the Dallas office of Gibson Dunn, where he is a member of the firm’s Appellate and Constitutional Law Practice Group.

Ben has presented oral argument in the Texas Supreme Court, the United States Court of Appeals for the Fifth, Second, and Seventh Circuits, and the Texas Appellate Courts. He has also often represented clients before the United States Supreme Court and other state and federal courts of appeals. In addition, Ben often handles critical or dispositive motions in both state and federal trial courts.

Prior to rejoining Gibson Dunn, Ben worked as lead counsel for commercial appellate matters for the world’s largest retailer. Ben also has a distinguished record of public service in state and federal government. As Deputy Solicitor General in the Office of the Texas Solicitor General, he successfully briefed and argued many of the state’s most important appeals and advised on many of the state’s most important trial court matters. As Deputy Assistant Attorney General in the Department of Justice’s Office of Legal Policy, Ben lead for the Department’s efforts to confirm federal judicial nominees, including Justice Amy Coney Barrett and over eighty lower court judges. Earlier in his career, Ben served as Counsel to Senator Ted Cruz on the Senate Judiciary Committee and as Special Counsel to Senator Cruz for the confirmation of Justice Brett Kavanaugh.

Ben clerked for Judge Diarmuid F. O’Scannlain of the United States Court of Appeals for the Ninth Circuit and later for Judge James C. Ho of the United States Court of Appeals for the Fifth Circuit. Ben received his law degree with honors from the University of Chicago Law School and his Bachelor of Arts degree from Washington and Lee University magna cum laude with honors in history.

Ben is a member of the Texas Bar. He is admitted to practice before the Second, Fifth, Seventh, and Ninth Circuits and before the U.S. District Courts for the Northern and Western Districts of Texas.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Jenn L. Mascott

Judge, U.S. Court of Appeals for the Third Circuit

Biography

Hon. Jennifer Mascott served as Associate Professor of Law and Director of the Separation of Powers Institute at The Catholic University of America’s Columbus School of Law before her appointment to the federal bench. On July 16, 2025, President Donald J. Trump nominated her to the U.S. Court of Appeals for the Third Circuit (Delaware), and she was confirmed on October 9, 2025.

Prior to her confirmation, Judge Mascott wrote extensively in administrative and constitutional law, statutory interpretation, and the separation of powers. Her scholarship—published in leading journals including the Stanford Law Review, Notre Dame Law Review, and Supreme Court Review—was cited by the U.S. Supreme Court and multiple federal courts. She also contributed Supreme Court commentary for NBC Universal.

Before joining Catholic Law, she was an Assistant Professor and Co-Director of The C. Boyden Gray Center at George Mason University’s Antonin Scalia Law School. In 2022 she became co-author of Beermann, Cass & Diver’s Administrative Law: Cases and Materials (9th ed.). In 2023 she received the Justice Joseph Story Award for excellence in scholarship, teaching, and advancing the rule of law.

Judge Mascott also served as a Council Member of the ABA’s Administrative Law Section and as a Public Member of the Administrative Conference of the United States. She frequently testified before Congress on executive power, regulatory reform, and judicial jurisdiction, and participated in multiple Supreme Court confirmation hearings.

From 2019 to 2021, she took leave from academia to serve as Deputy Assistant Attorney General in the Department of Justice’s Office of Legal Counsel and later as Associate Deputy Attorney General, where she argued federal cases and assisted with Justice Amy Coney Barrett’s confirmation. Earlier in her career, she clerked for Justice Clarence Thomas and for then-Judge Brett M. Kavanaugh on the D.C. Circuit.

Judge Mascott earned her J.D. summa cum laude from the George Washington University Law School and her B.A. from the same institution.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Chad A. Readler

Judge, United States Court of Appeals, Sixth Circuit

Biography

Judge Readler earned his undergraduate and law degrees from the University of Michigan. After graduating, he served as a law clerk to Judge Alan Norris of the United States Court of Appeals for the Sixth Circuit. Judge Readler then began practicing law in the Columbus office of the international law firm Jones Day, eventually spending ten years as a partner in the firm’s Issues and Appeals Practice Group. While at Jones Day, Judge Readler appeared in state and federal trial and appellate courts around the country, most frequently the Supreme Court of Ohio and the Sixth Circuit. Judge Readler also successfully argued before the United States Supreme Court in McQuiggin v. Perkins on behalf of an inmate claiming actual innocence. His other pro bono representations include representing capital defendants before the Tenth Circuit and the Supreme Court of Ohio, as well as representing defendants sentenced to life in prison before the Sixth Circuit. While at Jones Day, Judge Readler traveled to Nairobi with Lawyers Without Borders to train Kenyan lawyers in prosecuting domestic violence cases, and he was also a recipient of the American Marshall Memorial Fellowship awarded by the German Marshall Fund of the United States. Following his career in private practice, Judge Readler served as Acting Assistant Attorney General for the Civil Division of the United States Department of Justice from 2017 to 2019. In that role, Judge Readler led and supervised over 1,000 lawyers in the Department’s largest litigating division, briefing and arguing several cases on behalf of the United States in federal courts across the country, including high-profile cases significant to the Administration and the Department.  In March 2019, Judge Readler was confirmed to serve as a Circuit Judge on the Sixth Circuit. He resides in Columbus.

Tara Leigh Grove

Vinson & Elkins Chair in Law, University of Texas at Austin School of Law

Biography

Tara Leigh Grove is the Vinson & Elkins Chair in Law at the University of Texas School of Law. Grove graduated summa cum laude from Duke University and magna cum laude from Harvard Law School, where she served as the Supreme Court Chair of the Harvard Law Review. Grove clerked for Judge Emilio Garza on the U.S. Court of Appeals for the Fifth Circuit, and then spent four years as an attorney for the U.S. Department of Justice, Civil Division, Appellate Staff, where she argued fifteen cases in the courts of appeals.

Grove’s research focuses on the federal judiciary, interpretive theory, and the constitutional separation of powers. She has published with such prestigious law journals as the Harvard Law Review, the Yale Law Journal, the Columbia Law Review, the University of Pennsylvania Law Review, the New York University Law Review, the University of Chicago Law Review, the Virginia Law Review, the Texas Law Review, the Cornell Law Review, the Northwestern University Law Review, and the Vanderbilt Law Review. Grove has received awards for both her research and her teaching.

In 2021, Grove served on the Presidential Commission on the Supreme Court of the United States, a bipartisan commission created by President Biden and charged with examining proposals for Supreme Court reform. Since 2022, Grove has worked on the Princeton Initiative on Reclaiming the Constitutional Powers of Congress, which brings together former members of Congress, political scientists, and law professors. Grove serves as the Co-Chair of the section on the Appointments Process for the Princeton Initiative. Grove is a co-author of Low & Jeffries' Federal Courts and the Law of Federal-State Relations, a leading federal courts casebook, and she has served as the Chair of the Federal Courts Section of the Association of American Law Schools. Grove has been a visiting professor at both Harvard Law School and Northwestern Pritzker School of Law.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Jenn L. Mascott

Judge, U.S. Court of Appeals for the Third Circuit

Biography

Hon. Jennifer Mascott served as Associate Professor of Law and Director of the Separation of Powers Institute at The Catholic University of America’s Columbus School of Law before her appointment to the federal bench. On July 16, 2025, President Donald J. Trump nominated her to the U.S. Court of Appeals for the Third Circuit (Delaware), and she was confirmed on October 9, 2025.

Prior to her confirmation, Judge Mascott wrote extensively in administrative and constitutional law, statutory interpretation, and the separation of powers. Her scholarship—published in leading journals including the Stanford Law Review, Notre Dame Law Review, and Supreme Court Review—was cited by the U.S. Supreme Court and multiple federal courts. She also contributed Supreme Court commentary for NBC Universal.

Before joining Catholic Law, she was an Assistant Professor and Co-Director of The C. Boyden Gray Center at George Mason University’s Antonin Scalia Law School. In 2022 she became co-author of Beermann, Cass & Diver’s Administrative Law: Cases and Materials (9th ed.). In 2023 she received the Justice Joseph Story Award for excellence in scholarship, teaching, and advancing the rule of law.

Judge Mascott also served as a Council Member of the ABA’s Administrative Law Section and as a Public Member of the Administrative Conference of the United States. She frequently testified before Congress on executive power, regulatory reform, and judicial jurisdiction, and participated in multiple Supreme Court confirmation hearings.

From 2019 to 2021, she took leave from academia to serve as Deputy Assistant Attorney General in the Department of Justice’s Office of Legal Counsel and later as Associate Deputy Attorney General, where she argued federal cases and assisted with Justice Amy Coney Barrett’s confirmation. Earlier in her career, she clerked for Justice Clarence Thomas and for then-Judge Brett M. Kavanaugh on the D.C. Circuit.

Judge Mascott earned her J.D. summa cum laude from the George Washington University Law School and her B.A. from the same institution.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Chad A. Readler

Judge, United States Court of Appeals, Sixth Circuit

Biography

Judge Readler earned his undergraduate and law degrees from the University of Michigan. After graduating, he served as a law clerk to Judge Alan Norris of the United States Court of Appeals for the Sixth Circuit. Judge Readler then began practicing law in the Columbus office of the international law firm Jones Day, eventually spending ten years as a partner in the firm’s Issues and Appeals Practice Group. While at Jones Day, Judge Readler appeared in state and federal trial and appellate courts around the country, most frequently the Supreme Court of Ohio and the Sixth Circuit. Judge Readler also successfully argued before the United States Supreme Court in McQuiggin v. Perkins on behalf of an inmate claiming actual innocence. His other pro bono representations include representing capital defendants before the Tenth Circuit and the Supreme Court of Ohio, as well as representing defendants sentenced to life in prison before the Sixth Circuit. While at Jones Day, Judge Readler traveled to Nairobi with Lawyers Without Borders to train Kenyan lawyers in prosecuting domestic violence cases, and he was also a recipient of the American Marshall Memorial Fellowship awarded by the German Marshall Fund of the United States. Following his career in private practice, Judge Readler served as Acting Assistant Attorney General for the Civil Division of the United States Department of Justice from 2017 to 2019. In that role, Judge Readler led and supervised over 1,000 lawyers in the Department’s largest litigating division, briefing and arguing several cases on behalf of the United States in federal courts across the country, including high-profile cases significant to the Administration and the Department.  In March 2019, Judge Readler was confirmed to serve as a Circuit Judge on the Sixth Circuit. He resides in Columbus.

Jenn L. Mascott

Judge, U.S. Court of Appeals for the Third Circuit

Biography

Hon. Jennifer Mascott served as Associate Professor of Law and Director of the Separation of Powers Institute at The Catholic University of America’s Columbus School of Law before her appointment to the federal bench. On July 16, 2025, President Donald J. Trump nominated her to the U.S. Court of Appeals for the Third Circuit (Delaware), and she was confirmed on October 9, 2025.

Prior to her confirmation, Judge Mascott wrote extensively in administrative and constitutional law, statutory interpretation, and the separation of powers. Her scholarship—published in leading journals including the Stanford Law Review, Notre Dame Law Review, and Supreme Court Review—was cited by the U.S. Supreme Court and multiple federal courts. She also contributed Supreme Court commentary for NBC Universal.

Before joining Catholic Law, she was an Assistant Professor and Co-Director of The C. Boyden Gray Center at George Mason University’s Antonin Scalia Law School. In 2022 she became co-author of Beermann, Cass & Diver’s Administrative Law: Cases and Materials (9th ed.). In 2023 she received the Justice Joseph Story Award for excellence in scholarship, teaching, and advancing the rule of law.

Judge Mascott also served as a Council Member of the ABA’s Administrative Law Section and as a Public Member of the Administrative Conference of the United States. She frequently testified before Congress on executive power, regulatory reform, and judicial jurisdiction, and participated in multiple Supreme Court confirmation hearings.

From 2019 to 2021, she took leave from academia to serve as Deputy Assistant Attorney General in the Department of Justice’s Office of Legal Counsel and later as Associate Deputy Attorney General, where she argued federal cases and assisted with Justice Amy Coney Barrett’s confirmation. Earlier in her career, she clerked for Justice Clarence Thomas and for then-Judge Brett M. Kavanaugh on the D.C. Circuit.

Judge Mascott earned her J.D. summa cum laude from the George Washington University Law School and her B.A. from the same institution.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Chad A. Readler

Judge, United States Court of Appeals, Sixth Circuit

Biography

Judge Readler earned his undergraduate and law degrees from the University of Michigan. After graduating, he served as a law clerk to Judge Alan Norris of the United States Court of Appeals for the Sixth Circuit. Judge Readler then began practicing law in the Columbus office of the international law firm Jones Day, eventually spending ten years as a partner in the firm’s Issues and Appeals Practice Group. While at Jones Day, Judge Readler appeared in state and federal trial and appellate courts around the country, most frequently the Supreme Court of Ohio and the Sixth Circuit. Judge Readler also successfully argued before the United States Supreme Court in McQuiggin v. Perkins on behalf of an inmate claiming actual innocence. His other pro bono representations include representing capital defendants before the Tenth Circuit and the Supreme Court of Ohio, as well as representing defendants sentenced to life in prison before the Sixth Circuit. While at Jones Day, Judge Readler traveled to Nairobi with Lawyers Without Borders to train Kenyan lawyers in prosecuting domestic violence cases, and he was also a recipient of the American Marshall Memorial Fellowship awarded by the German Marshall Fund of the United States. Following his career in private practice, Judge Readler served as Acting Assistant Attorney General for the Civil Division of the United States Department of Justice from 2017 to 2019. In that role, Judge Readler led and supervised over 1,000 lawyers in the Department’s largest litigating division, briefing and arguing several cases on behalf of the United States in federal courts across the country, including high-profile cases significant to the Administration and the Department.  In March 2019, Judge Readler was confirmed to serve as a Circuit Judge on the Sixth Circuit. He resides in Columbus.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

Biography

Professor Aaron Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. Before joining the faculty, he served as Solicitor General of Texas and represented Texas before the U.S. Supreme Court and the Texas Supreme Court, as well as overseeing all appellate litigation for the State. Earlier in his career, he was a professor at Brigham Young University and an appellate and antitrust partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also clerked for Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

As Solicitor General, Professor Nielson successfully defended against a First Amendment challenge Texas’s law requiring online pornographers to institute age verification. In 2020, the U.S. Supreme Court appointed him to defend the constitutionality of a federal agency. He currently serves as a Senior Fellow of the Administrative Conference of the United States after completing a six-year term as an appointed public member and chair of the Conference’s Administration & Management Committee.

Nielson’s research focuses on administrative law, federal litigation, and the separation of powers. He has published (or soon will publish) in the Harvard Law Review, Columbia Law Review, University of Chicago Law Review, University of Pennsylvania Law Review, Duke Law Journal, Georgetown Law Journal, Cornell Law Review, and Northwestern University Law Review, among others. Nielson has been recognized for teaching for teaching and scholarship and in 2021 received the Federalist Society’s Joseph Story Award, which recognizes a young academic for excellence in legal scholarship, a commitment to teaching, and a concern for students, and who has made a significant public impact in a manner that advances the rule of law in a free society. He is also an elected member of the American Law Institute.

Professor Nielson received his J.D. magna cum laude from Harvard Law School and an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree summa cum laude from the University of Pennsylvania, majoring in economics and political science.

Aaron Nielson

Charles I. Francis Professorship in Law, University of Texas at Austin School of Law

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