The Biden administration is urging the U.S. Supreme Court to spurn requests by Republican legislative leaders and their allies to block anyone who hasn’t provided proof of citizenship from casting a ballot in this year’s race between Kamala Harris and Donald Trump.

In a new filing Friday, Solicitor General Elizabeth Prelogar told the justices that lower courts got it right when they concluded that the National Voter Registration Act overrides a 2022 state law that restricts who can cast a ballot in the presidential race. She said while states are free to regulate who can vote in their own elections – including what documentation they need to provide – Congress has made it clear that only it has the authority to decide eligibility for federal elections.

Strictly speaking, the latest legal filings by House Speaker Ben Toma and Senate President Warren Petersen along with the Republican National Committee do not ask for a final ruling on whether the state can restrict who can vote for president. Instead, they ask that the state be allowed to enforce the 2022 law while its legality is litigated.

But what they want would have a real and immediate impact.

There are currently more than 41,000 Arizonans who registered to vote using a form authorized by the National Voter Registration Act. And that form does not require proof of citizenship but only an avowal, under penalty of perjury, that the individual is qualified to cast a ballot.

A ruling in favor of what the two GOP leaders and the national party want would bar them from voting for president this year.

What makes that particularly significant is that Biden beat Trump four years ago by just 10,457 votes. And attorneys for those seeking to bar presidential voting this year in Arizona suggest the votes of those federal-only voters are unlikely to swing the way of the GOP contender.

They point out in legal filings that Republicans make up about 34% of the state’s registered voters. But the latest figures from the Secretary of State’s Office show just 14.3% of these federal-only voters signed up as Republicans.

Another 27.4% are Democrats, with 53.6% listed as “party not designated” and the balance among minor parties.

Central to all this is the interplay between the National Voter Registration Act and the 2022 law.

The former allows people to register using the federal form. And the Supreme Court itself, in a 2013 ruling involving Arizona, said the state must “accept the federal form as a complete and sufficient registration.”

In 2022 state lawmakers said when someone registers using the federal form, county recorders must use certain databases to verify the person’s citizenship access. If the recorder cannot verify citizenship, even for a reason like not having access to necessary databases, the person then is told he or she must provide “documentary proof of citizenship.”

More to the point, the law says anyone who fails to provide that proof is ineligible to vote in presidential elections.

The state already has conceded they cannot bar these people from casting ballots in congressional elections. That’s because the Constitution allows Congress to dictate the “time, place and manner” of such races.

But Toma, Petersen and the Republican National Committee, in their own filings this week, argue that doesn’t apply to presidential races, allowing lawmakers to impose the restriction.

Not true, Prelogar told the justices.

“This court has repeatedly recognized that Congress has power to regulate presidential elections and primaries,” she wrote. Consider, Prelogar said, a federal law that prohibits the use of force and threats in presidential elections, citing an 1884 case.

“The court also has upheld federal campaign finance laws that apply to presidential elections,” she continued, saying that the justices concluded that constitutional provisions allow Congress “to protect the election of the president and vice president from corruption.”

And then there’s the difference between state and federal elections.

“The president represents all the voters in the nation, and presidential elections implicate a uniquely important national interest,” Prelogar said. “Congressional regulation of presidential elections thus in no sense invades any exclusive state power.”

If nothing else, she said the amendments to the Constitution adopted after the Civil War empowered Congress to enact the National Voter Registration Act to prohibit racial discrimination in voting.

That issue came up last year when U.S. District Court Judge Susan Bolton first blocked the state from enforcing the law.

“Congress found that discriminatory and unfair registration laws and procedures can have a direct and damaging effect on voter participation in elections for federal office and disproportionately harm voter participation by various groups, including racial minorities,” the judge wrote. “It is the duty of federal, state and local governments to promote the exercise of the fundamental right to vote.”

Multiple other filings Friday with the Supreme Court underline the partisan nature of the legal dispute.

The Arizona Republican Party, in its own legal brief, said what makes it a state issue is that, strictly speaking, Arizonans are not voting for president. Instead, attorney Harmeet Dhillon said they are choosing the electors who, in turn, will vote in the Electoral College for who should be president and vice president.

“Under settled Supreme Court precedent and a historical record dating back to the Constitutional Convention, a state’s presidential electors are state officials,” she said. And Dhillon said the Constitution gives states complete power to decide how they will appoint presidential electors.

A similar argument was made to the high court by Kris Kobach, the attorney general of Kansas on behalf of himself and 23 other Republican attorneys general. And he told the justices that barring Arizona from enforcing the 2022 law would result in “irreparable harms to Arizona’s sovereign interests.”

On the other side of the equation, Arizona Attorney General Kris Mayes, a Democrat, filed her own arguments urging the justices to leave intact the lower court rulings barring the state from enforcing the 2022 law, arguing that changing the system now, three months before the general election, “would be destabilizing.”

Anyway, she told the justices, it is her office and not Toma and Petersen who represent the state’s interests in federal court.

And a separate legal filing by the state and national Democratic parties says there’s no basis for the justices to intercede now, saying those who want the justices to step in have failed to show they would suffer “irreparable harm,” one of the legal standards to stay the lower court rulings.

The case before the court is about more than who can cast a ballot for president.

A separate provision of the 2022 law says these federal-only registrants must cast a ballot in person and cannot vote by mail, even for the congressional races in which they are entitled to vote.

Prelogar acknowledged that federal law leaves it to each state to decide whether, and to what extent, to allow mail voting.

“Having made mail voting generally available, however, Arizona may not discriminatorily withhold that option from voters who submit the federal form without accompanying documentary proof of citizenship,” she wrote.

There is no date for the justices to decide whether they want to consider the requests by the Republicans and, if so, whether they will allow the state to enforce the 2022 law this year.