As leaders wrangle over a potential deal to avert the fiscal cliff, many rank-and-file members are quietly resigned to compromise and are holding back from criticizing the ongoing talks.

It’s a distinct change of tone from the fiery summer of 2011, when lawmakers of both parties were unrestrained in voicing their discontent. The four party caucuses met Tuesday to review the current offers on the table and to map out backup plans in case talks between President Barack Obama and Speaker John A. Boehner, R-Ohio, collapse, as they did two summers ago.

But with less than two weeks until the automatic spending cuts and tax increases are scheduled to take effect, many lawmakers seem flexible about what they might accept.

“Most of my colleagues realize that we’re in negotiations. Neither of us are going to get everything we want,” Sen. Thomas R. Carper, D-Del., said upon exiting his party’s weekly meeting, where the White House’s top legislative aide, Rob Nabors, briefed members.

“We clearly need to raise revenues. We clearly need to find ways to save money in entitlement programs,” Carper continued, noting that Obama is committed to doing both. He said he believes his colleagues could support a deal that has taxes and additional spending cuts.

The same even-keeled approach, at least publicly, was on display in the House. Boehner huddled with his caucus twice to outline his decision to vote later this week on measures that would raise taxes on the wealthy. After the first session, members were more subdued than usual, according to aides and lawmakers.

“The comments were pretty mellow, all the way around,” Rep. Rob Bishop, R-Utah, said.

According to House Republican aides, GOP leaders are planning to bring their “plan B” to the floor as soon as Thursday. Under that proposal, the House would vote on two amendments: One that would allow tax rates to go up on those making more than $250,000 — as Senate Democrats have called for — and one that would allow tax rates to go up on those making more than $1 million. The latter would also include extensions of the estate tax and a fix to make sure the alternative minimum tax does not hit middle-income taxpayers.

At the evening meeting of House Republicans, Rep. Tom Price of Georgia suggested allowing members to vote on every tax bracket, choosing which Bush-era tax rates they would like to extend. But leadership was lukewarm to the measure, according to a source in the room.

Even some staunch conservatives did not rule out the idea of voting for Boehner’s $1 million plan. Rep. Mick Mulvaney of South Carolina likened a vote for the backup proposal to the debt ceiling votes — a necessary evil — but he indicated that he and others may need some sweeteners to consider a tax rate increase.

“I voted to raise the debt ceiling, which is something I never thought that I would do, but I did that because of cut, cap and balance. It would fix the system. I’ll consider anything that fixes the system,” he said referencing a bill that would have required passage of a balanced-budget amendment to raise the debt ceiling. House Republicans passed it in 2011, but it died in the Senate.

Though Democratic leaders such as Senate Majority Leader Harry Reid of Nevada slammed the GOP plan to pass a millionaires’ tax some Democrats championed just last year, the public sparring appeared to be a sideshow. Both parties look to be coming closer in both rhetoric and policy. The subtle convergence of long-held talking points was as telling a sign as any that a deal may yet be forged by the end of the year.

“It is a reality that taxes are going to go up as it is, so we should characterize this in the simplest, most straightforward way that we can, and that is, ‘Any effort on the part of the House right now will be to reduce taxes, not increase them,’” said conservative Rep. Trent Franks, R-Ariz., in an attempt to reframe the debate among Republicans.

Of course, not everyone is holding their fire as the White House and speaker continue to trade proposals. Some of the most conservative members of the House Republican Conference left the morning meeting fuming. When asked if he would support Boehner’s “plan B,” Rep. Raúl R. Labrador of Idaho said, “I’m a hell no.”

Republican Study Committee Chairman Jim Jordan of Ohio said that allowing anyone’s taxes to go up is a concession he and others simply may not be willing to make.

“Once you cross that line and say, ‘It’s OK for some people’s taxes to go up,’ I think it’s a mistake for the Republican Party,” he said.

Many others were hoping after the morning meeting for more specifics before they made up their minds. That may be why Republican leaders added the estate and AMT provisions. Members coming out of the morning meeting were under the impression that the bill would be a clean extension of the lower tax rates. And it’s also why GOP leaders called for the second session on Tuesday evening.

And, of course, not every Democrat is pleased either. The White House’s most recent offer included raising the threshold for tax hikes from those making more than $250,000 to $400,000. It also included “chained CPI,” which changes the calculation of the consumer price index in order to limit cost-of-living increases for programs, including Social Security.

Sen. Jeff Merkley of Oregon released a statement after the caucus meeting with Nabors. “We had an election, and the voters sent a message to Congress to focus on jobs and fairness,” Merkley said. “The formula we use to adjust cost-of-living changes for seniors needs to reflect the real costs they face, not the budgetary fantasies of Washington.”

Jonathan Strong contributed to this report.