President Biden took the border fight directly to former President Donald J. Trump on Tuesday, blaming his predecessor and putative challenger for torpedoing a bipartisan immigration agreement out of crass politics at the expense of national security.
Weighing in forcefully after months of largely staying out of the fray, Mr. Biden called on congressional Republicans to “show some spine” and stand up to Mr. Trump. But he effectively acknowledged that the deal negotiated over several months was doomed and vowed to make it a campaign issue against the opposition.
“All indications are this bill won’t even move forward to the Senate floor,” Mr. Biden said in a speech televised from the White House. “Why? A simple reason. Donald Trump. Because Donald Trump thinks this is bad for him politically.”
The president said Mr. Trump would “rather weaponize this issue than actually solve it” and has leaned on Republicans to block it.
“It looks like they’re caving,” he added. “Frankly, they owe it to the American people to show some spine and do what they know to be right.”
The decision by Republicans to reject a bipartisan border deal that they had previously demanded not only paralyzed the immigration debate but also imperiled security assistance for Ukraine and Israel attached to the $118 billion measure, closing off what had been seen as the best remaining avenue to aid embattled American allies.
The deadlock raised questions about whether Congress would be able to salvage the emergency aid package and, if so, how. Speaker Mike Johnson sought to advance aid to Israel alone by pushing a separate $17.6 billion measure but it ran into strong resistance from hard-right Republicans as well as Democrats and Mr. Biden, who threatened a veto.
The result was a vivid portrait of congressional dysfunction. Rather than pursue the border crackdown they had once sought, Republicans in the House spent the day trying to impeach Alejandro N. Mayorkas, the homeland security secretary, on charges that he willfully refused to enforce border laws. With even some Republicans calling the move a stunt, it was not clear that Mr. Johnson had the votes to prevail.
The disarray and discord on Capitol Hill, punctuated by the president’s sharp speech at the White House, underscored how much this year’s presidential election has already come to shape the debate in Washington nine months before the vote. In effect, two presidents, one incumbent and one former, are clashing over some of the most pressing issues facing the United States, each vying in a way to set the direction for the country even before voters make their choice in November.
Mr. Biden, who for most of his presidency has avoided even using Mr. Trump’s name, referring to him only as “the former guy” or other elliptical phrases, has in recent weeks seemed increasingly eager to confront the former president more directly, culminating in Tuesday’s speech.
The president privately complained that the initial draft of the address was not pointed enough in attacking Mr. Trump and wanted it toughened, according to a senior administration official, who spoke on the condition of anonymity. He and aides then tested out tougher phrases shortly before he went before cameras to deliver it more than an hour after originally scheduled.
“I understand the former president is desperately trying to stop this bill because he’s not interested in solving the border problem,” Mr. Biden said. “He wants a political issue to run against me on.”
“Republicans have to decide,” he added. “Who do they serve? Donald Trump or the American people?”
He called the bipartisan agreement “a win for America” because it combines the “most fair, humane reforms” to immigration law and “the toughest set of reforms to secure the border” at a time of record illegal migration. To buttress his point, he cited support from institutions normally favorable to Republicans, including the Wall Street Journal editorial page, the U.S. Chamber of Commerce and the National Border Patrol Council, a union that endorsed Mr. Trump in 2016 and 2020.
“If this bill fails, I want to be absolutely clear about something,” Mr. Biden said. “The American people are going to know why it failed. I’ll be taking this issue to the country.”
The reason, he said, is Republican fear of their front-runner.
“They’re afraid of Donald Trump,” Mr. Biden said. “Every day between now and November, the American people are going to know that the only reason the border is not secure is Donald Trump and his MAGA Republican friends.”
The president is coming late to the debate. While he has supported the bipartisan negotiations, he has largely kept away from them personally and not waged a high-profile public fight for a deal. Aides said he wanted to avoid complicating the talks by making them about him. But some Democrats were frustrated that he had not taken a more prominent role until now.
The president’s speech was in part aimed at some Democrats who have already criticized provisions in the border bill that would make it harder for migrants to gain asylum in the United States. If fellow Democrats vote against the measure, it could make it more difficult for Mr. Biden to frame his party as the one seeking solutions in the face of Republican intransigence.
Mr. Trump has been privately consulting with Mr. Johnson and other congressional Republicans and publicly laid down his opposition to the agreement on social media.
“Only a fool, or a Radical Left Democrat, would vote for this horrendous Border Bill,” the former president wrote, even though the measure was negotiated by one of the most conservative Republicans on Capitol Hill, Senator James Lankford of Oklahoma.
Republicans have fallen in line, including many who initially favored the bill, which includes measures to toughen border security but none of the provisions offering a pathway to citizenship for illegal immigrants already in the country that have historically been insisted on by Democrats. Critics on the right complained that it nonetheless did not go far enough to tighten the border.
“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 on Tuesday. “I cannot vote for this bill. Americans will turn to the upcoming election to end the border crisis.”
Senator Mitch McConnell, Republican of Kentucky and the minority leader, who was initially supportive of the deal, told reporters at a news conference that his conference “had a very robust discussion about whether or not this product could ever become law” and was influenced by Mr. Johnson’s declaration that it would be “dead on arrival” in the House.
“It’s been made pretty clear to us by the speaker that it will not become law,” Mr. McConnell said. Asked if he had misread his fellow Republicans, Mr. McConnell said: “I followed the instructions of my conference who were insistent that we tackle this in October. It is actually our side that wanted to tackle the border issue. We started it. Obviously with a Democratic president and a Democratic Senate, our negotiators had to deal with them.”
Mr. Johnson cheered the Senate Republican reversal over the border deal. “It may be on life support in the Senate,” he told reporters. “We welcome that development.”
Mr. Biden argued that Republicans were not just sacrificing a border compromise, but also abandoning Ukraine during its war against President Vladimir V. Putin’s Russia.
“We can’t walk away now,” he said, wearing a striped tie with the blue and yellow colors of the Ukrainian flag. “That’s what Putin’s betting on. Supporting this bill is standing up to Putin. Opposing this bill is playing into his hands.”
The grim reality, however, was that the once-strong bipartisan consensus for aid to Ukraine was fraying. In an unusual letter, a group of U.S. ambassadors stationed in the Indo-Pacific region urged congressional leaders on Monday to secure passage of the legislation, which also includes aid to Taiwan, saying that America’s credibility with its strategic partners is on the line.
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 the president would be enough to push new funding to Ukraine across the finish line.
But a restive G.O.P. voter base is dead set against sending another round of taxpayer money 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, Republican of Florida and a Trump ally, was exultant on social media. He cited a line from the film “Apocalypse Now”: “I love the smell of napalm in the morning!”
Katie Rogers, Erica L. Green, Carl Hulse, Karoun Demirjian, Zolan Kanno-Youngs and Michael D. Shear contributed reporting.