Benjamin Weiss

WASHINGTON (CN) — Senate Republicans completed their about-face on a bipartisan border security bill Wednesday, voting down a procedural motion that would have allowed the upper chamber to begin debate on the measure.

Republicans’ move to scuttle the legislation — negotiated as a compromise with the Senate’s Democrat majority — was the climax of days of souring rhetoric among lawmakers on the proposed measure.

Sen Jon Tester voted in support of the bill and Sen. Steve Daines voted in opposition.

The upper chamber voted 49 to 50 not to advance the bill, falling short of the 60-vote threshold needed to begin debate. Several Democrats, including New Jersey Senator Bob Menendez and Massachusetts Senators Elizabeth Warren and Ed Markey, joined Republicans in shooting the measure down.

GOP Senators James Lankford, Lisa Murkowski, Susan Collins and Mitt Romney voted in favor of the bill.

If made law, the $118 billion legislation would have enacted several border security provisions Republicans have championed for months, including stricter rules for migrants claiming asylum in the U.S. and mandates for shuttering the border under certain circumstances. The bill would have coupled immigration policy with foreign aid for Israel and Ukraine.

Initially, it appeared as though the bipartisan compromise would be able to clear the upper chamber. But, after Senate negotiators, led by Lankford and Connecticut Senator Chris Murphy, unveiled the text of their measure over the weekend, things quickly took a turn for the worse as more and more lawmakers on both sides of the aisle came out against the legislation.

Republicans also faced pressure from former President Donald Trump, who urged the Senate to reject a border compromise.

Democrats on Wednesday blasted their Republican colleagues for killing the legislation, a move which they saw as a purely partisan maneuver.

“I’m profoundly disappointed,” Senate Majority Whip Dick Durbin said of GOP lawmakers, writing in a statement that they “cowered to the demands of Donald Trump.”

Montana Senator John Tester said it was “shameful that politicians in Washington have once again chosen to play politics with our border and put our national security at risk.”

And Senator Martin Heinrich of New Mexico said: “Republicans failed the American people. All to preserve a political talking point.”

Democrats have speculated that Senate Republicans flipped on the proposed border compromise to keep immigration on the ballot for November’s presidential election. That suggestion was bolstered this week by comments from some top Senate Republicans such as Wyoming Senator John Barrasso, who said in a statement that “Americans will turn to the upcoming election to end the border crisis.”

The end of the Senate’s border bill comes just a day after House Republicans failed to approve a measure providing standalone funding for Israel — House Speaker Mike Johnson’s answer to the upper chamber’s legislation which he has long opposed. House lawmakers also failed on Tuesday to advance an effort to impeach Homeland Security Secretary Alejandro Mayorkas.