Early one morning last March, I received a phone call from David Barron, who had recently begun working for the Obama Administration as Deputy Assistant Attorney General in the Justice Department’s Office of Legal Counsel (OLC). David and I had been colleagues at OLC during the Clinton Administration. I stayed on the OLC staff to work for President Bush, and David moved on to become a member of the Harvard Law School faculty. We remained on friendly terms. David was calling to give me a head’s up that later in the day the Justice Department would be releasing ten OLC memoranda from the Bush Administration, two of which I had co-authored. (I was, and am, very grateful to David for his thoughtfulness.) ...