Washington — The Senate voted Tuesday to begin a marathon debate session over the SAVE America Act, an elections bill that President Trump has been pressing Republicans in Congress to pass, despite its dim prospects in the upper chamber.

For months, conservatives have rallied around the legislation, which would require proof of citizenship to register to vote, along with photo ID to cast a ballot. And Mr. Trump upped the ante last week when he threatened not to sign most other bills until Congress passes the SAVE America Act, adding to growing calls for Republicans to maneuver around the Senate's 60-vote filibuster threshold. 

But Senate Majority Leader John Thune has been clear in recent weeks that Republicans don't have the votes to do so. Instead, he has promised a "full and robust debate" on the legislation this week, teeing up discussion on the Senate floor that could last a week or more. 

In a 51 to 48 vote, the Senate advanced the measure Tuesday afternoon. Republican Sen. Lisa Murkowski of Alaska voted with all Democrats against the move. 

Tuesday's vote begins what's expected to be a lengthy debate. Rather than moving to cut it off with a vote, Thune will allow senators to discuss the measure on the floor for as long as they want.

With 53 Republicans in the Senate, support from Democrats is needed to reach the 60-vote threshold to advance most legislation. And since GOP leaders are opting against deploying the so-called "talking" filibuster — which would gum up the Senate floor for weeks and require near-unanimous support from the GOP conference — the bill has no chance of passing.

But the exercise will force Democrats to take uncomfortable votes on amendments, while attempting to appease conservatives with ample floor time to make their case on the legislation that Mr. Trump has prioritized above all others. 

"The votes aren't there to do a talking filibuster. And so what we are doing is we are having a fulsome debate on the floor of the United States Senate," Senate Majority Leader John Thune, a South Dakota Republican, told reporters Tuesday morning. "We'll have it up, everybody will have their say. At some point we'll have votes, and we'll see where the votes are."

Republicans have framed the legislation as uncontroversial, comparing the voting requirements to the process of getting a library card. But experts say the bill would have implications for millions of Americans who don't have access to certain documents, like a passport or their birth certificate, or those who have changed their names. 

Noncitizens cannot legally vote in federal elections, and instances of noncitizens voting are rare. But polling suggests Americans are supportive of voter ID and proof of citizenship requirements. Ahead of the 2024 election, more than 8 in 10 Americans were in favor of requiring voters to show photo ID, according to Gallup, along with requiring those who are registering to vote for the first time to show proof of citizenship.

Trump says SAVE America Act will "guarantee" midterm victory

After the president demanded that Congress pass the SAVE America Act last week and threatened a legislative blockade, he stressed to House Republicans that passing the measure will "guarantee" that Republicans win the midterm elections in November. He claimed that Democrats only oppose it because "they want to cheat." 

"They know that if we get this, they probably won't win an election for 50 years," Mr. Trump said. 

In addition to the current legislation, the president has also demanded that lawmakers add a ban on all mail-in ballots, along with unrelated provisions to ban transgender athletes from participating in women's sports and bar gender-affirming surgeries for minors.

Senate Minority Leader Chuck Schumer argued at a news conference Tuesday that the legislation is a "naked attempt to rig our elections."

"The SAVE Act is not about protecting the vote, it's about making it harder to vote — and easier to steal an election," said Schumer, a New York Democrat.

Schumer noted during a press call on Sunday that Democrats support voter ID, but argued that "this is not a voter ID bill."

"This is about purging the voter rolls in a massive way, so you never even get the chance to show a voter ID when you showed up to vote because you'd be knocked off the rolls," Schumer said. 

The Trump administration has demanded complete voter registration lists from nearly every state and the District of Columbia. At least a dozen states have turned over their voter rolls or say they intend to, according to the Brennan Center for Justice, while the Justice Department has filed lawsuits against a number of states that have refused.

The SAVE America Act would require states to take steps to ensure only U.S. citizens are registered to vote, including by establishing a program where the state identifies individuals who are not U.S. citizens. And the voter ID requirement in the bill says that if the ID does not indicate the person is a citizen, they would need proof of citizenship documents to vote, unless a state has submitted its voter registration list to the federal government and has indicated that the voter has been verified as a citizen. 

How Democrats plan to approach the lengthy floor debate on the legislation remains to be seen. Schumer said Monday that "not a single Democrat" will support the measure, while promising to oppose Republican efforts to "burn time on this legislation here on the floor."

Thune said Republicans expect "continued, full-throated opposition to voter ID and the SAVE America Act from Senate Democrats."

"Republicans are looking forward to this debate," he added.