Violating the Twenty-Seventh Amendment
In March 1873, Congress was about to adjourn and decided to vote itself a retroactive pay increase of $7,000. This was an especially sweet deal for lame-duck members like John Bingham who did not have to face the wrath of the voters. Unfortunately for him, outrage at this “Salary Grab” led the next Congress to rescind the bonus.
I think this is the only time that the command of the Twenty-Seventh Amendment was violated (“No law, varying the compensation for the services of the Senators and Representatives, shall take effect, until an election of Representatives shall have intervened.”). Of course, that Amendment was not in force then, but is there another examples of a congressional pay hike that was contrary to this text?