The Senate raced on Thursday to revive a sweeping emergency aid bill for Ukraine and Israel that has stalled yet again on Capitol Hill, with senators starting a critical vote to advance the legislation while Republicans bickered over whether they should help keep it alive.
Senator Chuck Schumer, Democrat of New York and the majority leader, pushed forward with the next procedural step toward taking up the bill, which would provide $60.1 billion for Ukraine, $14.1 billion for Israel and $10 billion in humanitarian aid for civilians in global conflicts. He did so despite the uncertainty plaguing the Republican conference, where many senators who voted on Wednesday to block a version of the measure that included border restrictions were still withholding their support.
Many demanded the chance to propose changes, including adding border restrictions — just hours after having blocked the legislation that included a bipartisan package of border restrictions. But after Republicans huddled behind closed doors in the Capitol on Thursday morning, it was still unclear whether they would be able to iron out their disputes.
The bill needs 60 votes to keep advancing, which would require the support of at least 10 Republicans — and even if they are successful, additional procedural hurdles remain. In a sign that leaders expected the measure to move forward, Senators Mitch McConnell of Kentucky, the minority leader, and John Thune of South Dakota, the No. 2 Republican, both cast early votes in favor of advancing the bill.
The impasse over the foreign aid bill was the latest manifestation of discord that has roiled the G.O.P. and ground efforts to pass national security spending bills to a standstill. Republicans have clashed over how to address international crises without angering the leader of their party and its likely presidential nominee, former President Donald J. Trump.
Senate Republicans had initially signaled early Wednesday that they were likely to support moving forward with a clean foreign aid bill without border provisions as long as they had opportunities to propose changes, terms that Mr. Schumer agreed to in principle. Leaders on both sides were optimistic that they would have enough backing to speedily advance the measure.
But by evening, their optimism had given way to confusion, as Republicans devolved into a familiar crouch, torn between rival factions and utterly unable to make a decision about how to proceed. They spent much of Wednesday afternoon and evening squabbling over which amendments to insist on — and some argued privately they should not allow the bill to move forward at all.
Shortly after 7 p.m., Mr. Schumer sent senators home to “give our Republican colleagues the night to figure themselves out,” promising to reconvene the Senate at noon Thursday. But by Thursday morning, G.O.P. senators still had not settled on a way ahead — and it was unclear whether they would be able to resolve their differences anytime soon.
Republican senators are split, with some staunchly supportive of sending a fresh infusion of military aid to help Ukraine fight off a Russian invasion, and those on the right deeply opposed to doing so. And some G.O.P. senators who back the aid are nonetheless concerned that doing so without exacting a price from Democrats would compromise them politically in an election year, given Mr. Trump’s opposition to backing Ukraine’s war effort.
Some Republican senators are likely to back the bill regardless of whether it is changed on the floor, so long as they are given a chance to have the Senate vote on some proposed revisions. Eight Republicans — Senators Mitch McConnell of Kentucky, the minority leader; Susan Collins of Maine; John Kennedy of Louisiana; Jerry Moran of Kansas; Lisa Murkowski of Alaska; Mitt Romney of Utah; Thom Tillis of North Carolina; and Todd Young of Indiana — already voted to advance the measure past an opening procedural hurdle on Wednesday. Some said they intended to keep supporting the bill.
“I’m likely going to be there on the back end of the process,” Mr. Tillis said on Thursday, adding that the Senate owed it to Ukraine — and every other country that was still supporting its war against Russia — to see the bill through. “Failing to take this up is exactly what Putin hopes happens this week, and I’m going to do everything I can to prevent it.”
But other Republicans who have championed aid to Ukraine are still withholding their support. They included Senators Lindsey Graham of South Carolina, John Cornyn of Texas and James Lankford of Oklahoma. Mr. Lankford spent the past four months negotiating a bipartisan deal to pair Ukraine funding with border security measures, a trade-off Republicans had demanded, only to have it rejected by Republicans on Wednesday.
“I’m not giving up on the border,” Mr. Graham said in an interview, despite having voted earlier on Wednesday to kill the Ukraine aid and border deal.
Among the border-related amendments that had been floated by Republicans were a measure reflecting Mr. Lankford’s border deal and a more severe immigration enforcement bill that House Republicans passed last spring.
There were also talks about a bid to revoke or change the Flores settlement agreement, which sets limits on how long children can be held in detention facilities, according to Senate aides who described the discussions on the condition of anonymity because no decision had been made about whether to pursue the proposal.
Some Republican senators emerged from the party’s morning meeting on Thursday saying they also wanted amendment votes to change the foreign aid portions of the bill before committing their support.
“I’m still very focused on trying to limit the humanitarian component,” said Senator Dan Sullivan, Republican of Alaska, arguing that European countries could focus on sending economic and humanitarian aid to Ukraine while “we focus on weapons and our own industrial base.”
But other Republican senators signaled there was no amendment deal that would be enough to secure their vote.
“That’d be window dressing,” said Senator Mike Braun, Republican of Indiana. “Whenever the other side allows you to do amendments, it’s never ones they think will pass.”
Democrats also have a wish list of proposed changes to the measure. Nearly 20 Democratic senators, most of them from the left wing of the party, have signed on to an amendment that would require recipients of security aid to use weapons in accordance with U.S. law, international humanitarian law and the laws of armed conflict — and not hamper efforts to send humanitarian aid to civilians. While the measure does not specifically mention Israel, it was inspired by senators’ concerns about that country’s bombardment of the Gaza Strip running afoul of international law.
Whether any of those senators will have a chance to propose their preferred changes depends on whether the chamber can move on to the next procedural vote to advance the bill. And while some Republicans sounded hopeful that they could resume voting soon, others opposed to the legislation pledged to make the process as long and painful as possible.
“I will insist on every minute and every day of it,” said Senator Rand Paul, Republican of Kentucky. “I want to be here a week, because I want to talk about what a disaster the bill is and what a mistake it is to send our money to other countries before we fix our own problems here.”
Carl Hulse contributed reporting.