The decision by Republicans in Congress to torpedo a bipartisan border deal they demanded has left the fate of aid to Ukraine and Israel in peril, closing off what had been seen as the best remaining avenue on Capitol Hill for approval of critical military aid to American allies.
The political paralysis in the face of pleas from President Biden, lawmakers in both parties and leaders around the world for quick action raised immediate questions about whether Congress would be able to salvage the emergency aid package — and if so, how.
The result was a vivid portrait of congressional dysfunction at the hands of Republicans. After helping to kill a border crackdown they had insisted upon, they were set to spend the day in the House trying to impeach Alejandro N. Mayorkas, the homeland security secretary, on charges that he has willfully refused to enforce border laws.
Dug in against the border deal and new aid to Kyiv, the House also was set on Tuesday to try to push through legislation sending $17.6 billion in military assistance to Israel. But that measure, which omits help for Ukraine or humanitarian aid for Palestinians, was facing steep resistance from hard-right Republicans, who complained that the money was not paired with spending cuts. It also faced opposition from Democrats and Mr. Biden, who has threatened a veto, calling the bill a cynical attempt to pre-empt the security legislation brokered in the Senate.
Representative Hakeem Jeffries of New York, the Democratic leader, told lawmakers on Tuesday morning that he and the party’s top leaders would oppose the Israel-only bill, saying that while they were “prepared to support any serious, bipartisan effort” to help Israel, the legislation was “not being offered in good faith.”
That raised questions about whether the measure, which Republicans are bringing up under special rules that require a two-thirds majority for approval, could pass the House.
The $118.3 billion Senate bill, which is set for a test vote on Wednesday, appeared to be dead even before it reached the floor, after an increasing number of Republicans — even those who led the charge to negotiate it — declared they would vote to block it.
“Joe Biden will never enforce any new law and refuses to use the tools he already has today to end this crisis,” Senator John Barrasso of Wyoming, the No. 3 Republican, said. “I cannot vote for this bill. Americans will turn to the upcoming election to end the border crisis.”
The grim reality appeared to be sinking in for the nation’s allies and diplomatic leaders who for months have anxiously watched and hoped for momentum on Capitol Hill for approving aid, despite clear signs that the strong bipartisan consensus for such a measure was fraying.
In an unusual letter, a group of U.S. ambassadors stationed in the Indo-Pacific region had urged congressional leaders on Monday to secure passage of legislation providing assistance to Ukraine, Israel and allies in the Pacific, saying America’s credibility with its strategic partners is on the line.
But what Mr. Biden and others had hoped might be a temporary political problem standing in the way of such an effort instead appeared to be a fundamental change in the dynamic in Congress that could doom it completely.
For months, many in the White House and abroad had followed conventional wisdom and assumed that the combined will of a handful of like-minded congressional leaders, national security committee chairs and Mr. Biden would be enough to push new funding to Ukraine across the finish line.
“The reality of hard-power competition simply does not wait for the president or Congress to take it seriously,” Senator Mitch McConnell, Republican of Kentucky and the minority leader, said on Tuesday.
But a restive G.O.P. voter base is dead set against sending another round of aid to Ukraine, and rank-and-file Republicans, especially in the slim-majority House, have flexed their muscles to oppose any real movement.
After reports indicated there was no clear path ahead for Congress to approve aid to Ukraine and Israel on Tuesday morning, Representative Matt Gaetz of Florida was exultant on social media. He cited a line from the film “Apocalypse Now”: “I love the smell of napalm in the morning!”
