But however foolish the firing of Mueller might be, the notion that Congress has the power to prevent the president from discharging anyone who works in the executive branch of government is on very shaky ground. The Senate has been here before, and the precedent isn’t one that should reassure Flake or any of his colleagues who think they are defending the Constitution against Trump.

The most prominent example of Congress trolling a president in this manner took place in 1867 when Congress passed and then overrode a presidential veto of the Tenure of Office Act. That legislation was a thinly veiled effort by a Republican Congress to hamstring President Andrew Johnson, a Democrat who had succeeded the assassinated Abraham Lincoln after being elected vice president on a Unionist ticket in 1864. Johnson opposed efforts to defend freed former slaves and to pursue a radical reconstruction of the South in the aftermath of the Civil War. More to the point, Johnson wanted to fire Secretary of War Edwin Stanton, a Lincoln holdover who used federal troops to stop violence against African Americans.

The Tenure of Office Act denied the president the right to fire anyone confirmed to their positions in the federal government by the advice and consent of the Senate without senatorial approval. Johnson fired Stanton anyway and the Senate denied its consent for his removal. When Johnson insisted on preventing Stanton from continuing to serve, it led to impeachment and then a Senate trial where Johnson evaded conviction and removal from office by a single vote. That effort was really a referendum on Johnson’s lamentable refusal to defend Reconstruction. But as subsequent court rulings agreed, Congress had overstepped its bounds in seeking to prevent Johnson from getting rid of officials that he didn’t like.