Senate Poised to Advance Ukraine Bill as G.O.P. Splinters

A bipartisan coalition of senators was on track Monday to push a $95 billion foreign aid package to the brink of passage, as Republicans fractured bitterly over the bill.

Over the past week, 18 Republicans have rallied around the legislation, helping to advance it through the Senate despite the full-throated opposition of the bulk of G.O.P. senators, Republican leaders in the House and the party’s likely presidential nominee, Donald J. Trump.

Mr. Trump and his right-wing allies have been pressuring Senate Republicans relentlessly to abandon the legislation, which would direct $60.1 billion toward helping Ukraine fight off a Russian invasion, $14.1 billion toward Israel’s war against Hamas and almost $10 billion toward humanitarian aid for civilians in conflict zones, including Palestinians in Gaza.

Mr. Trump in particular has been railing against the legislation from the campaign trail. In recent days, he has cheered G.O.P. senators for killing an earlier version of the bill that included a bipartisan deal on border security, argued on social media that it was “stupid” for the United States to offer foreign aid instead of loans, and encouraged Russia to “do whatever the hell they want” to NATO members that did not spend enough money on their own defense.

But the pressure appeared to have backfired, at least partially, in the Senate, where by Monday, more than a third of Republicans had cast multiple votes to keep the aid bill moving forward — and their coalition appeared to be holding firm.

“It overall accomplishes the goals that we wish to accomplish, if you want to keep Russians from killing Americans, push back on the C.C.P., and support our ally Israel,” Senator Bill Cassidy, Republican of Louisiana, said of the bill on the floor during a rare weekend session on Sunday evening, referring to the Chinese Communist Party. He accused his Republican colleagues of “dishonesty” in the way they were characterizing the legislation. “We in the Senate owe it to the American people to vote the honest truth and get something done.”

Many of the Republicans opposing the bill argue that it prioritizes foreign conflicts over the threat that a major influx of migrants poses to the United States. That is despite their vote last week to kill a version of the legislation that would have also stiffened border enforcement by restricting asylum laws, increasing detention capacity and accelerating deportations.

“We didn’t have a serious debate to fix a broken border,” Senator Lindsey Graham, Republican of South Carolina, said on the floor Sunday. Mr. Graham said he planned to vote against the bill — and skip a conference with European allies this week in favor of making a trip to the southwestern border.

“You can tell our friends and allies that I want to help them, but we have a national security nightmare in our own backyard,” Mr. Graham added.

Other Republican opponents have argued that it would be folly to send Ukraine the tens of billions of dollars included in the bill — and that doing so would compromise Mr. Trump’s ability to cut off aid to Kyiv in the future should he win the election.

“The supplemental represents an attempt by the foreign policy blob/deep state to stop President Trump from pursuing his desired policy,” Senator J.D. Vance, Republican of Ohio, wrote in a memo to his colleagues. He added that Democrats were trying to “provide grounds to impeach him and undermine his administration.”

Democrats warned Republicans that a vote against the foreign aid bill would only help Russia pummel Ukraine on the battlefield, and would come back to haunt them.

“The entire world is going to remember what the Senate does in the next few days,” Senator Chuck Schumer, Democrat of New York and the majority leader, said on the floor. “If some people think Putin is just going to stop at Ukraine, if they think it’s somehow better to reason with him, to appease him, to hear him out, then these modern-day Neville Chamberlains ignore the warnings of history: The appetites of autocrats are never-ending.”

Republicans have insisted for months that they would not vote for military assistance for Ukraine unless Congress — or President Biden — also took steps to crack down on a surge of migration across the southwestern border. But when the death of the border bill refocused the debate around Ukraine, a subset of Republicans pivoted and fell in line behind the aid to Kyiv.

“I know it’s become quite fashionable in some circles to disregard the global interests we have as a global power, to bemoan the responsibilities of global leadership,” Senator Mitch McConnell, Republican of Kentucky and the minority leader, said on the floor Sunday, repudiating the anti-Ukraine faction of his party. “This is idle work for idle minds, and it has no place in the United States Senate.”

Republican opponents of the bill were also still pushing for the opportunity to offer proposals to change it, but as of Monday afternoon, Democrats and Republicans had been unable to strike a deal to do so.

“We haven’t even been able to make a single amendment pending,” Senator Mike Lee, Republican of Utah, complained in a lengthy tirade on the floor on Monday, arguing that the process was “not fair.”