AS LONG AS IT TAKES…. As of a week ago, the Senate Democratic leadership hoped to wrap up the lame-duck session by this Friday, December 17. Among the issues leaders have every intention of trying to address before going home are the tax deal, New START ratification, DADT repeal, defense authorization, the DREAM Act, a revised food-safety bill, and probably a few other things I’m forgetting.

In other words, something’s gotta give. Either the Senate delays the end of the session or it dramatically scales back its to-do list, leaving key priorities undone.

Senate Armed Services Committee Chairman Carl Levin (D-Mich.), to his credit, told C-SPAN over the weekend that he’d like to see the chamber remain in session after Christmas to help get its work done. What I found odd, though, is Levin argue that it’s a “problem” that President Obama hasn’t called “urged the Senate to stay in, right up to New Year’s.”

The more the president is prepared to fight for these priorities, the better. But with due respect to Levin, since when is it the White House’s job to help set the Senate’s legislative schedule? Can’t members figure this out on their own?

Fortunately, there were some fresh indications that Friday will not be the end of the session. CQ had this piece today on ratifying the pending nuclear arms treaty.

“We’ll be here as long as it takes to get it done,” Regan LaChapelle, spokeswoman for Majority Leader Harry Reid, D-Nev., said Dec. 10. Her comments echoed White House spokesman Robert Gibbs, who earlier that day said, “Congress won’t leave before START is done.”

What’s more, Senate Minority Leader Mitch McConnell (R-Ky.) asked Reid this morning about the likelihood of weekend work. The Majority Leader replied, “We need to stay here until we finish.”

That’s exactly the right attitude to have — and it suggests it’s probably safe to ignore last week’s talk about wrapping up the year by Friday.

The longer they’re in session, the more they can at least try to do. It also helps shift the onus onto Republican obstructionists — they can go home sooner if they simply let the chamber function at a reasonable pace.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.