By David A. Fahrenthold, the Washington Post

On Capitol Hill Monday, moderate legislators were in an uncomfortable spot. Again.

It was right-wing Republicans who pushed for a showdown over the national debt ceiling. But, after a bipartisan deal was reached on Sunday night, many of those same Republicans said they could not support it.

Rep. Joe Walsh (R-Ill.), for instance, said he was very pleased that Republicans had won so much in this deal.

“Thank God for these troublesome Republicans that have been sent to Congress,” said Walsh, a freshman allied with the tea party movement. “We’ve changed the conversation.”

So would Walsh vote for the deal he had helped win?

“No,” he said. Walsh, like others in the House, wanted more drastic cuts, and a balanced budget amendment to the Constitution. “We have to do something dramatic. And this isn’t it.”

On Monday, that left leaders from both parties pressing their moderate members to support the legislation, with the threat of a national default looming on Tuesday.

Heading into a closed-door meeting with House Democrats Monday morning, Minority Leader Nancy Pelosi (D-Calif.) said it was “very disconcerting” that the deal requires “not one red cent” from wealthy Americans. But she praised the proposal for raising the debt limit for 18 month and said the deal would protect Medicare and Medicaid.

She said she would hear out the concerns of fellow Democrats, a number of whom indicated as they entered the meeting that they planned to vote against the deal. “This package is what we were able to achieve,” Pelosi said.

It’s not exactly a tempting proposition: groups on the right and the left have already begun to bash the compromise.

But Rep. Charlie Dent (Pa.), active in a group of moderate Republicans, said he felt an obligation to vote yes. “We all have an affirmative obligation to govern,” Dent said--and that means voting to avoid default.

“I’ve expressed some frustration and anger to some of my colleagues here,” that they’ve decided they couldn’t vote for the proposition, Dent said. “I heard too much from some of my colleagues about what they could never do,” he said, instead of what they could.

On the other side of the House aisle, Rep. Mike Ross (Ark.) is a leader among the “Blue Dog” Democrats, a group of moderate members. He said he is leaning toward a “yes” vote to approve the debt-ceiling deal.

“Whether it’s a Democratic majority or a Republican majority, moderates in both parties are the ones that end up saving the day,” in votes like this one, Ross said.

Former Rep. Tom Davis (R-Va.) said it’s a position moderates have found themselves in before. After the approval of the Troubled Asset Relief Program in 2008, for instance, Republicans who voted “yes” were attacked for their votes in party primaries.

Davis — who now leads an organization of centrist Republicans — said he worried that history could repeat itself for those who vote to raise the debt ceiling today.

“This thing smells OK today,” Davis said. “But, the further out you get from it, the more it’s going to stink,” as the urgency of the debt crisis fades and conservative groups examine the details.

Still, Davis said, he felt dozens of Republican moderates would still vote “yes.”

“That’s kind of their lot in life, that they always are the grownups,” Davis said. “They’re always the ones that are willing to be part of a deal.”