“I hope in the next 24, 36 hours we can get something we agree on. If not, we’re going to move forward on what I think needs to be done,” Reid told reporters.

Reid’s trump card in negotiations with Senate Republican Leader Mitch McConnell (Ky.) is the threat he will change Senate rules with a simple majority vote, a tactic known as the nuclear option. This maneuver would allow Reid to change the Senate rules with a simple majority vote, something that has never been done, according to parliamentary experts.

Critics call it the nuclear option but proponents, such as Sen. Tom Udall (D-N.M.) say it is more accurate to describe it as the “Constitutional option” because the Constitution empowers each chamber to set its own rules.