A project labor agreement (“PLA”) is a union collective bargaining agreement that all contractors must sign to work on a construction project. In Boston Harbor, the Supreme Court held that a government entity acting as an owner-developer of a public construction project could lawfully require compliance with a union-only PLA, without running afoul of federal preemption, on the presumption that a private owner-developer could lawfully take the same action. As a result of this 1993 decision, the use of PLAs on public construction projects has dramatically increased....