Bipartisan Senate negotiators have reached an agreement on an infrastructure deal that would spend hundreds of billions in new federal dollars while also not increasing taxes, a key GOP red line. But lawmakers face an uphill struggle as they work to sell this to the White House and their fellow lawmakers.
Conservatives previously opposed the more than roughly $300 billion in new spending and many Democrats are demanding more than double the price tag for traditional infrastructure and climate-related investments.
"Our group -- comprised of 10 Senators, 5 from each party -- has worked in good faith and reached a bipartisan agreement on a realistic, compromise framework to modernize our nation's infrastructure and energy technologies," the senators said in a statement. "This investment would be fully paid for and not include tax increases."
Though the negotiators have struck a deal, they've not yet released details of their proposal.
The group has kept the scope of the package more narrow than what President Joe Biden and many Democrats have pushed, according to Sen. Lisa Murkowski, R-Alaska.
"It's a narrower scope than what the White House is proposing on what I think most people would define as hard infrastructure, where we're talking about building things," said Murkowski.
The White House said it was briefed by Democratic senators involved in the negotiations on the deal.
"Questions need to be addressed, particularly around the details of both policy and pay fors, among other matters," the White House said in a statement. "Senior White House staff and the Jobs Cabinet will work with the Senate group in the days ahead to get answers to those questions, as we also consult with other Members in both the House and the Senate on the path forward."
It's not yet clear what the overall price tag of the bill will be, but the bipartisan group is expected to propose far more in new spending than the $378 billion pitched by Republican negotiators and rejected by the White House.
The president, in his most recent discussions, insisted on $1 trillion in new spending on public works projects, but Republicans claim that in their private conversations, Biden said he could be open to a deal that includes far less, around $600 billion.
An aide familiar with negotiations said the bipartisan package includes $579 billion in new spending and is worth about $974 billion over five years, including previously allocated funds. When spread over eight years, a funding window preferred by the White House, the aide said the cost of the bill would be $1.2 trillion.
The package is also expected to account for funding that congressional committees have already approved -- or are expected to approve -- this year, including an already-passed $35 billion water bill and a pending $305 billion highway funding bill.
There are no tax increases, a non-starter for Republicans, in the package. There are also no user fees, like tolls, which Democrats reject.
The package does propose indexing the 18.4-cent gas tax to inflation to secure some revenue, according to Sen. Mitt Romney, R-Utah. Biden has opposed this measure unequivocally, saying it would violate the president's promise not to raise taxes on those making less than $400,000 a year, according to a source familiar with the White House's thinking.
Negotiators also depend on tax enforcement by the IRS to pay for some of the bill, according to Sen. Jon Tester, D-Mont., something Biden has supported. It's not clear that these things alone would be enough to fund the entirety of the proposal.
"The bipartisan conversations have been good. They've been robust. They've been lengthy. And I think we've made some good progress. We've gotten to a pretty good point," Murkowski said. "We've defined and refined the scope, which I think has been critically important, because it's hard to talk about what you're paying for unless you've agreed on the scope. And so I think we're in a good place."
Now comes the far more difficult task of selling their proposal to Senate colleagues.
"What is happening now is, as Republicans and Democrats, we are going out to folks within our respective conferences, talking about the contours of what we've put together to see what that level of support might be," Murkowski said. "And the conversations that I have been part of have been very promising."
But one Republican leader on Thursday gave the group reason to hope.
"There may be a path. It's probably a narrow path," the Senate's No. 2 Republican, John Thune of South Dakota, told reporters. Any legislation would require 60 votes to overcome an expected filibuster.
The group has a track record of success. Most of the members crafted the more than $900 billion measure that formed the foundation of a sweeping COVID relief compromise bill that passed Congress in December.
"Beauty is in the eye of the beholder," Tester said. "For some people, it's going to be plenty. For others, it's not going to be enough. I think there's going to be challenges for both Republicans and Democrats, because this isn't perfect legislation. It's a compromise."
Some Democrats have expressed skepticism that the bipartisan group can make good on some of the more robust social priorities Biden aimed to tackle in his original infrastructure proposal, like green energy, home care, child care and funding for schools.
"There's no guarantee that there's 50 Democratic votes for whatever this group works out," Sen. Chris Murphy, D-Conn., said Thursday. He cited concerns over a lack of funding for environmental priorities.
"I share the worries of others that the direction that the discussions are heading in are not necessarily going to be able to unite the Democratic caucus," Murphy added.
But Majority Leader Chuck Schumer, D-N.Y., has made clear this week that he does not intend to sacrifice Democratic priorities in the name of bipartisanship. Schumer had said if the bipartisan group came to an agreement that he would use a fast-track budget procedure known as reconciliation to push through all of the remaining Democratic infrastructure priorities with just 50 Democratic votes.
"We continue to move on two tracks, a bipartisan path and a reconciliation path," said Schumer. "Both are moving forward."
It is not yet clear if Schumer would have the necessary support to pass those priorities on a party-line vote.
ABC News' Mary Bruce contributed to this report.