Border Deal Fails Again in the Senate as Democrats Seek Political Edge

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.