Amar points to two cases to support his argument: Morrison v. Olson in 1988 and Myers v. United States in 1925. The Morrison case upheld the 1978 Independent Counsel Act, passed in the wake of Richard Nixon ordering the Saturday Night Massacre, which created a special executive-branch position that could be used to investigate malfeasance by high-ranking federal officials and whose occupant could not be fired by the president without cause. While this outcome would, at first blush, seem to support the Mueller bill, a number of liberal legal scholars have endorsed the late Justice Antonin Scalia’s dissent in Morrison, in which he argued the law usurps presidential power. As recently as 2015, sitting Justice Elena Kagan called it “one of the greatest dissents ever written and every year it gets better.” The Independent Counsel Act was eventually allowed to sunset after the Iran-Contra and Whitewater investigations, with both parties having felt subject to partisan crusades by unaccountable prosecutors.

Meanwhile, Myers suggests conservative justices would support Trump. The majority opinion in that case—authored by the chief justice and former president William Howard Taft—concluded that the president can fire executive-branch officials without congressional consent. Amar notes that Myers’s reasoning was recently cited in the majority opinion in a 2010 case, Free Enterprise Fund v. Public Company Accounting Oversight Board. “The Constitution that makes the President accountable to the people for executing the laws also gives him the power to do so,” wrote Chief Justice John Roberts, who was joined by his fellow conservatives. “That power includes, as a general matter, the authority to remove those who assist him in carrying out his duties.” Since 2010, the high court has retained its executive-power-friendly conservative majority, and its Democratic appointees may have lost a dissenting vote: John Paul Stevens, one of the dissenters in Free Enterprise Fund, was replaced by Kagan.