The Senate has worked continuously since 2:00 P.M. Wednesday, and it looks as if it will work Thursday into Friday night.

The all-night sessions kicked off Wednesday when Senate Republicans refused to yield back time on nominations in reaction to Senate Democrats' move last month to change filibuster rules using the so-called "nuclear option." Republicans did not back down today, spending hours speaking about everything from their displeasure with the rules change to the failures of Obamacare.

"What passed for gridlock before, this will pale in comparison to the poison that seeps from the hands of those who are careless and reckless with the law," Sen. Rand Paul, R-Ky., said. "Where the filibuster once created conversation, the iron-fisted rule of the rule breakers will stifle it."

But Senate Democrats saw the talk-a-thon as another example of obstruction that led to the rules change in the first place.

"I think it speaks volumes as to what's been going on on the floor. It's the picture of why we had to change the rules around here," Senate Majority Leader Harry Reid said in a news conference Thursday. "We're wasting all this time post-cloture."

Since Wednesday, the Senate has confirmed at least five nominees. Reid hopes to confirm around six more nominees, including Jeh Johnson to be the next Secretary of Homeland Security, before the holiday recess.

The Senate floor may be open overnight so technically the Senate will be in session, but senators won't speak all night.

The longest Senate session ever occurred between Feb 29, 1960, and March 5, 1960, and resulted in a 125 hours 16 minute session during which "a bill to lease a building at Fort Crowder, MO was used as a vehicle for civil rights amendments," according to the Senate Historical Office. But even that session broke up for a 15-minute recess on March 2. The longest unbroken session during that period took 82 hours and 2 minutes from March 2 to March 5.

Sen. Ted Cruz's all-night filibuster earlier this year kept the Senate in session for 34 hours and 11 minutes.