House Republican leaders maneuvered Wednesday to round up support in the party for two major spending bills. Both are expected to pass the House, but it’s the size and makeup of the coalitions behind the bills that will help shape Washington’s fiscal debate over the next several months.

The first of the two votes is to come Thursday, on whether to affirm the hard-fought budget deal reached last week that averted a government shutdown. The six-month spending bill appears headed for passage with support on both sides of the political aisle. If that happens, it would indicate a bipartisan bloc of lawmakers who might be willing to compromise again later on acrimonious spending issues.

The second vote will come Friday over the GOP’s 2012 budget blueprint, crafted by Budget Committee Chairman Paul Ryan (R-Wis.), which would lower the nation’s long-term deficit by reining in spending and fundamentally overhauling Medicare and Medicaid.

That roll call will be partisan; no Democrat is expected to vote for the Ryan plan. For the more vulnerable freshman Republicans, the vote could become a defining marker that Democrats hope to use in reelection campaigns next year.

Lawmakers were digesting the 459-page short-term spending bill Wednesday as GOP leaders labored to win over as many rank-and-file Republicans as possible to demonstrate unity over the agreement made Friday by House Speaker John A. Boehner (R-Ohio).

The deal, which results in $38 billion in spending cuts over the five months remaining in fiscal 2011, has drawn high-profile detractors in the GOP. Thursday’s vote will be closely watched as an indicator of fissures between Boehner’s leadership team and the party’s tea party adherents, who had pushed aggressively for deeper spending cuts.

Any revolt among the 87 GOP freshmen could be interpreted as a prelude to the coming clash over the debt ceiling, when Congress will have to decide whether to increase the amount of money that the federal government can borrow.

“I’m wrestling with the magnitude of the $1.6 trillion deficit versus the relatively small amount that we are cutting and whether it is better to support $38 billion in cuts — which are woefully inadequate, but which are better than we otherwise would have — versus a vote against $38 billion in cuts as a signal that we really should’ve done better,” said freshman Rep. Mo Brooks (R-Ala.).

In that, Brooks has company.

“We changed the conversation here in Washington,” said Rep. Sandy Adams (Fla.), a tea-party-backed freshman who defeated a Democratic incumbent in an Orlando area swing district. But she said she was undecided on the budget deal.

“This is our day of reckoning,” said Rep. Ann Marie Buerkle (N.Y.), another swing-district freshman Republican. She, too, was undecided.

More than three months into the 112th Congress, House Republicans have yet to feel any pressure from the left on a vote. All of the GOP defectors have said that the leadership-backed spending bills did not go far enough to the right — and even Republicans in swing districts said they had not felt any pressure to slow down.

“It’s not ‘Oh, we don’t need to cut,’ ” said Rep. Cory Gardner (Colo.), who unseated a Democrat in the Denver exurbs. “It’s never been ‘You’re cutting too much.’ ”

Freshman Rep. Tim Huels­kamp (R-Kan.) said he would vote against the compromise as a “dollar-store deal” because the spending cuts do not go deep enough.

“Things went downhill — $100 billion to $61 billion to $38 billion,” Huelskamp said, referring to the initial amount of cuts that Republicans were seeking. “I’ve had 36 town halls, and when I told [people there] about anything less than $100 billion, they weren’t too happy with that.”

The divide in the Republican Party seemed to deepen Wednesday. Presidential candidate Tim Pawlenty, the former Minnesota governor, issued a strongly worded statement saying that the spending bill “should be rejected.”

There is less angst in the Senate, where leaders expected the bill to sail through with little drama.

“This deal’s already been cut, and it’s time to move on,” said Sen. John Cornyn (Tex.), chairman of the National Republican Senatorial Committee.

Some in the House see the chamber’s March 15 vote approving a stopgap funding bill as a benchmark for Thursday’s vote. In that roll call, 186 Republicans and 85 Democrats voted for the legislation; 54 Republicans rejected the measure.

This time, Boehner and other House leaders do not want that latter number to grow, but they conceded that they might need Democratic votes for the deal to pass.

That shouldn’t be a problem. Rep. Robert E. Andrews (D-N.J.), who has opposed the recent stopgap funding measures, said that he and other “no” votes are likely to instead back this deal because it calls only for most agencies to function on “95 percent of last year’s funding.”

“It’s a very sensible spending cut,” Andrews said.