At 6 p.m. all senators are supposed to meet in the Old Senate Chamber for a closed-door joint caucus. The purpose of the joint caucus is for senators to air grievances on filibuster rules.

"I look forward to the joint caucus," Reid said. 

Reid has threatened to use the “nuclear option” — changing the Senate rules with a simple-majority vote — in order to thwart Republican obstruction on seven of President Obama’s cabinet nominees. Republicans have complained that changing the rules would diminish minority rights in the Senate.

Last week, Reid filed cloture on seven of Obama’s nominees, some of which Republicans have objected to. If a deal isn’t reached sooner, there will be several procedural votes on the nominations Tuesday.

Nominees Democrats are hoping to vote for are Richard Cordray to be Director of the Bureau of Consumer Financial Protection; Richard Griffin, Sharon Block and Mark Pearce to the National Labor Relations Board; Fred Hochberg to be President of the Export-Import Bank; Tom PerezThomas Edward PerezClinton’s top five vice presidential picks Government social programs: Triumph of hope over evidence Labor’s 'wasteful spending and mismanagement” at Workers’ Comp MORE to be Secretary of Labor; and Gina McCarthyGina McCarthyOvernight Energy: EPA releases ozone findings | Lawmakers come out against Perry grid plan | Kids sue Trump on climate change Congress must come to terms on climate change regulation EPA to repeal landmark Obama climate rule MORE to be Administrator of the Environmental Protection Agency.