The Republican bid to provide $1 billion for President Trump’s White House ballroom project in a filibuster-proof budget bill hit a significant roadblock on Saturday when the Senate’s top parliamentary referee ruled that the money did not qualify to be included in the measure.
In a finding announced by Senate Democrats, Elizabeth MacDonough, the nonpartisan parliamentarian, determined that the proposed $1 billion for security enhancements for the ongoing White House project ran afoul of budget reconciliation rules.
The ruling by Ms. MacDonough, the arbiter of complex Senate rules, meant that the proposal would need to be adjusted or be subject to a 60-vote threshold. That would effectively kill the funding, since Democrats are uniformly opposed.
Democrats argued that the White House project went far beyond the scope of the Senate Judiciary Committee, which included the money in its portion of the legislation. It sent Republicans back to the drawing board to figure out how to salvage the funding, which was already threatening to become a political problem for the G.O.P.
“While we expect Republicans to change this bill to appease Trump, Democrats are prepared to challenge any change to this bill,” Senator Jeff Merkley of Oregon, the senior Democrat on the Budget Committee, said in a statement. “We cannot let Republicans waste our national treasure on a mission of chaos and corruption while turning a blind eye to the needs of the American people.”
The decision was a setback for the White House, which is seeking the money to help finance a pet project of the president as well as to demonstrate in a court challenge that Congress has blessed it.
Still, some Republicans were probably relieved at the decision, since it could spare them from a politically difficult vote in support of a project that polls show is unpopular. Its fate in the narrowly divided House was already uncertain.
Republicans had previously announced they were overhauling disputed provisions.
“Technical adjustments are a standard part of the budget reconciliation process,” a statement from Judiciary Committee Republicans posted on social media on Friday said. “Revisions and conversations with the parliamentarian are ongoing.”
Democrats have aggressively attacked the spending, saying it underscores the warped priorities of Republicans and Mr. Trump to be spending lavishly on a White House ballroom when gas prices and other consumer costs are soaring, with little relief from Washington. Even if the money is knocked out of the legislation, Democrats plan to make Republicans vote repeatedly on proposals tied to the ballroom spending.
“Republicans tried to make taxpayers foot the bill for Trump’s billion-dollar ballroom,” Senator Chuck Schumer of New York, the Democratic minority leader, said in a statement. “Senate Democrats fought back — and blew up their first attempt.”
Senate Republican leaders have consistently defended the money, saying it was sought by the Secret Service to assure the safety of the president, his family and other top officials and visitors to the White House.
Sean Curran, the head of the Secret Service, was on Capitol Hill last week to brief Republican senators. The Secret Service also distributed a breakdown that showed that only $220 million of the $1 billion would be spent directly on the White House project, with the remainder going to a variety of other security projects and programs.
Republicans in the House and Senate began pushing the $72 billion measure to fund Mr. Trump’s immigration crackdown through the remainder of the president’s tenure after Democrats refused to support money for Immigration and Customs Enforcement and Customs and Border Protection unless the White House agreed to new restrictions on federal officers.
The dispute followed the killing of two American citizens by immigration officers in Minnesota earlier this year and led to a nearly 80-day funding cutoff for the Homeland Security Department when negotiations proved unsuccessful.
Republicans said the resistance and the disruption at the agency left them no choice but to go outside normal spending channels to free up the money for the immigration push, though the addition of the money for the White House project came as something of a surprise.
On Thursday, the parliamentarian ruled that some other central elements of the proposed funding for the Homeland Security Department did not meet the budget rules for mainly technical reasons. Republicans were also revising those provisions to try to keep them in the legislation.
