The Ohio Clock corridor filled with media, Senate staff and lawmakers on a rare Sunday session. (Melina Mara/The Washington Post)

In the House, it was watch and wait Sunday afternoon. In the Democratic offices of the House Ways and Means Committee, aides said they were eating ice cream as they awaited word of a deal from across the Capitol.

Rep. Sander Levin (D-Mich.), ranking member on the tax-writing panel, said that the new GOP demands to include "chained CPI" as part of a short-term plan was "not a step forward."

"I think that they need to drop that," he said of Republicans.

But including "chained CPI" would be "extremely helpful" to ensure that some spending cuts occur alongside tax cuts for millions of Americans, said Rep. Tom Cole (R-Okla.).

"I think the White House was willing to put that on the table. Now they're trying to pull that back," he said, but added: "At the end of the day, I don't know that it's critical, because it's going to come up for discussion again. Sooner or later it's going to happen."

Cole predicted the Senate would eventually strike a deal Sunday, "because senators don't like to be blamed for anything around here."

But the Oklahoma lawmaker, a key ally of House Speaker John A. Boehner (R-Ohio), cautioned that any Senate deal must have at least some support from top House GOP leaders.

"I'm not optimistic about a math that says we're going to get 180 Democrats and 40 Republicans" pass a Senate deal, Cole said. "I don't know who those 40 are going to be if there's not some leadership support. And if there's leadership support, it won't be 40, it'll be over half."

And what about working over the New Year's weekend?

"It's part of the job, it's what you get paid by the American people to do," Cole said. "It's a privilege to participate, I just wish it was a more orderly, uplifting process."