(CNN) The Senate rejected a key White House priority Wednesday when it defeated a bill to claw back about $15 billion in previously appropriated government funding.
A procedural vote on the rescission package failed on 48-50 vote, an embarrassing defeat for Senate GOP leaders and the Trump administration.
The vote on the measure, which already passed the House, was held open for 90 minutes while GOP leaders worked to persuade all their members to back it.
But as Capitol officials readied for Vice President Mike Pence to arrive to break a possible tie vote, Sen. Richard Burr, R-North Carolina, unexpectedly emerged from the Republican cloakroom to vote against the bill.
His opposition, coupled with a "no" vote from Sen. Susan Collins, the moderate Republican from Maine, sunk the bill.
Burr voted against the legislation because it included $16 million in cuts to the Land Water Conservation Fund, one of his top priorities, according to an aide.
"It cut $16 million out of the Land and Water Conservation Fund. Period, end of sentence," Burr said later, explaining his vote.
Sen. Lisa Murkowski, an Alaska Republican, also struggled with her vote. As she headed to the floor, she told CNN, "I don't support any of this."
But after many long minutes of discussions with other senators she approached the dais and with a pained look in her face, voted "aye' and quickly departed.
None of the Democrats up for re-election, even those in red states won by Trump, voted for the bill, something GOP aides thought they might feel pressured to do.
Senate Majority Leader Mitch McConnell firmly endorsed the proposal in a floor speech Wednesday. He said the unspent funds from various agencies were ripe to be returned to taxpayers. He also said the money being rescinded was not related to the recent hard-fought budget agreement reached by Republicans and Democrats.
"This modest belt-tightening would in no way infringe on the bipartisan spending deal that senators on both sides agreed to earlier this year. This savings package is 100% unrelated to that agreement. Totally separate," McConnell said. "It simply pulls back a small amount of unspent funds from a variety of government accounts."
Democrats complained the pulling back the funding could undermine trust in the delicate process of approving appropriations bills that's underway now on the Senate floor because lawmakers would not be confident the difficult decisions they make and votes they cast would be final.
"In just the latest example of the cut first and ask questions later policies of the Trump administration, we are voting on a bill today that would claw back billions of dollars from children's health insurance, affordable housing investments, infrastructure, rural development and innovative energy programs," said Sen. Patrick Leahy of Vermont, the top Democrat on the Appropriations Committee. "For a White House who just forced through Congress a $1.9 trillion tax giveaway to billionaires and corporations, to defend these cuts as necessary to reduce the deficit is laughable. It is unconscionable."
In the grand scheme of the massive federal budget, $15 billion is a pittance. But for politicians, especially fiscally-conscious Republicans up for re-election, a vote in favor of the spending reductions, is something worth talking about on the campaign trail.
Even though the bill was defeated, those senators can still tell voters they tried.