Senate Republicans on Thursday blocked a bipartisan border enforcement bill for a second time this year, voting down legislation they initially insisted upon to stem a surge of migrants across the United States border with Mexico but then abandoned amid a right-wing backlash cheered on by former President Donald J. Trump.
The vote amounted to a political trap laid for Republicans by Senator Chuck Schumer, Democrat of New York and the majority leader. He scheduled it in hopes of using the bill’s second failure on the floor to highlight an election-year contrast with the G.O.P. on immigration, an issue that polls show is a major potential liability for President Biden and his party.
On a vote of 50 to 43, the measure failed to advance after falling well short of the 60 votes needed to move forward in the Senate. Four Democrats, who view the provisions in the border crackdown measures as too extreme, voted with almost all Republicans, who have condemned it as too lax, to block its advancement.
The bill would effectively mandate that the border be shut down to migrants altogether when numbers reach unmanageable levels, sealing it if the average number of migrants encountered by immigration officials exceeded 5,000 over the course of a week, or 8,500 on any given day — as has happened in recent months. The bill would allow the president to do so unilaterally if the average reached 4,000. And it would vastly expand detentions and deportations, by funding thousands of new Border Patrol agents and personnel, as well as investing in new technology to catch drug smugglers.
“Just like three months ago, Senate Republicans rejected the strongest and most comprehensive bipartisan border security bill Congress has seen in a whole generation,” Mr. Schumer said. “It’s a sad day for the Senate, a sad day for America.”
In recent weeks, Democrats have circulated memos highlighting how they plan to use Republican opposition to the bill to try to neutralize G.O.P. attacks on the Biden administration over its handling of the border. The number of migrants caught crossing the southern border of the United States has been at record highs during the Biden administration.
Senator Mitch McConnell of Kentucky, the Republican leader, slammed the Biden administration’s policies on the border, and he insisted that Mr. Biden take action using an executive order.
He called the legislation pushed by Mr. Schumer a “distraction.”
“The solution is a president who’s willing to exercise his authority to use the tools he already has at his disposal to start cleaning up this mess,” Mr. McConnell said.
Republicans initially insisted upon border enforcement legislation as a prerequisite for passing aid to support Ukraine in fighting Russia’s invasion. Mr. McConnell appointed Senator James Lankford of Oklahoma as the chief Republican negotiator, and he worked with Senators Christopher S. Murphy, Democrat of Connecticut, and Kyrsten Sinema, independent of Arizona, along with Biden administration officials, to reach a deal.
After months of negotiation, the group reached an improbable compromise in February.
The union that represents frontline Border Patrol agents endorsed the legislation.
But Speaker Mike Johnson declared the bill “dead on arrival,” arguing it fell well short of a hard-line conservative bill the House had passed along party lines. That legislation was met with opposition by Democrats, including at the White House, where officials said it would “cut off nearly all access to humanitarian protections in ways that are inconsistent with our nation’s values and international obligations.”
Mr. Trump waded into the standoff shortly thereafter, demanding that the bipartisan border bill be killed while taking full credit for its demise.
“As the leader of our party, there is zero chance I will support this horrible open borders betrayal of America,” Mr. Trump told his supporters at a January rally in Las Vegas. “I’ll fight it all the way. A lot of the senators are trying to say, respectfully, they’re blaming it on me. I say, that’s OK. Please blame it on me. Please.”
Mr. Johnson again on Wednesday called the legislation a “bad bill” and insisted on the Senate passing the Republicans’ more restrictive bill, which would reinstate several Trump-era immigration policies.
“It’s really a phony messaging exercise,” Mr. Johnson, the Louisiana Republican, said of Mr. Schumer’s move.
Mr. Lankford, who had initially defended the bipartisan bill he negotiated, voted against the legislation Thursday. He argued Mr. Schumer was now playing political games with the measure.
“Today I’m going to vote no on a bill that I think should pass, but there’s been no effort to really get it to pass,” Mr. Lankford said.
Only one Republican, Senator Lisa Murkowski of Alaska, voted to advance the legislation Thursday.
Four Democrats — Senators Cory Booker of New Jersey, Laphonza Butler of California, Edward J. Markey of Massachusetts, Alex Padilla of California — and two independents, Senator Bernie Sanders of Vermont and Ms. Sinema, voted against moving ahead on the bill.
Ms. Sinema condemned both parties, saying they were seeking to profit politically from the issue rather than making a real try at addressing it.
“There are big challenges facing the Senate and our country and, evidently, this is not a Senate interested in solving those challenges,” Ms. Sinema lamented.
But most Democrats had trumpeted the bipartisan bill’s provisions throughout the week. On Wednesday, several senators held a news conference to highlight its measures to counter fentanyl trafficking. The legislation would have increased funding for the Drug Enforcement Administration to dismantle cartels and funded new technology aiming to quickly detect fentanyl at checkpoints, leading to arrests.
Senator Catherine Cortez Masto, Democrat of Nevada, said she had met with Border Patrol agents who told her they need the extra agents and reinforcements the bill would have funded.
“They are overwhelmed and understaffed,” she said of the agents. “They need help.”
