Republicans and Democrats have done this "nuclear option" dance before.
In 2005, with 10 of President George W. Bush's judicial nominees held up over the course of 16 months, then-Senate Majority Leader Bill Frist, R-Tenn., made a bold threat. He'd use a simple majority to change Senate rules and keep Democrats from filibustering.
Democrats, including then-Senate Minority Leader Harry Reid, D-Nev., went ballistic. Reid called the strategy "an abuse of power."
"What the Republicans came up with was a way to change our country forever," Reid said in an interview on C-SPAN in 2008.
In the interview, he was asked if he would ever employ the nuclear option to keep the minority for slow-rolling nominations.
"As long as I am the leader, the answer is 'No.' I think we should just forget that. That is a black chapter in the history of the Senate. I hope we never ever get to that again because I really do believe it will ruin our country," Reid said.
How quickly the tables turn.
Mitch McConnell, R-Ky., when he was the majority whip in 2005, called the "nuclear option" a way to "restore the norms and traditions of the Senate." Now, he is calling it a move that "would violate every protection of minority rights that have defined the United States Senate for as long as anyone can remember."
"Senate Democrats are gearing up today to make one of the most consequential changes to the United States Senate in the history of our nation. And I guarantee you, it is a decision that, if they actually go through with it, they will live to regret," McConnell said on the Senate floor last week.
Republican and Democratic Senators will meet in the historic old Senate chamber Monday night to discuss their options before Reid holds a vote Tuesday on three appointments – Richard Griffin, Sharon Block and Mark Pearce – to the national Labor Relations Board; the appointment of Richard Cordray to be the director of the Consumer Financial Protection Bureau, Fred Hochberg to be the president of the Export-Import Bank, Thomas Perez to be the Secretary of Labor and Gina McCarthy to be the Administrator of the Environmental Protection Agency.
The debate to change the Senate rules is nothing new, however. It has been debated in the Senate since the 1940s. In 1975, a showdown between Republicans produced a compromise that lowered the filibuster threshold from two-thirds, or 67 senators, to three-fifths and 60 senators.