President Donald Trump floated the idea of delaying the Nov. 3 election, pointing to unsubstantiated concerns about mail-in voting.

“With Universal Mail-In Voting (not Absentee Voting, which is good), 2020 will be the most INACCURATE & FRAUDULENT Election in history. It will be a great embarrassment to the USA. Delay the Election until people can properly, securely and safely vote???” he tweeted July 30.

Trump has fairly unlimited power to tweet out suggestions. However, he can’t change the date of the election. Congress would have to pass a law first.

“Some legal issues are complex, but this one is not,” said Richard H. Pildes, a professor of constitutional law at New York University. “The president has no legal power to change the date of the election unilaterally.”

Many prominent Republicans, including Senate Majority Leader Mitch McConnellwere quick to dismiss Trump’s trial balloon.

“Never in the history of the country, through wars, depressions and the Civil War, have we ever not had a federally scheduled election on time,” McConnell told a Kentucky TV station. “We’ll find a way to do that again this Nov. 3.”

What is the law on setting Election Day?

The Constitution empowers Congress to set the date by which states must choose their presidential electors, according to a March report by the nonpartisan Congressional Research Service.

“Since 1845, Congress has required states to appoint presidential electors on the Tuesday after the first Monday in November, which represents the date by which voters in every state must cast their ballot for President,” the report states.

“The only way Congress could change this would be by enacting new legislation, which would require both a majority vote in the House and enough votes to overcome the filibuster rules in the Senate,” Pildes said

Presidential elections have never been delayed, and only once has a court taken the step of postponing a congressional general election, wrote Marc Elias, a Democratic lawyer who has been involved in multiple election-related lawsuits.

In 1982, a federal district court in Washington, D.C., struck down two Georgia congressional districts under Section 5 of the Voting Rights Act. The court postponed the general election to later in November for those districts.

Any effort to change the election date would run into other legal obstacles.

Presidential terms have a hard stop on Jan. 20, wrote George Washington University law professor Jonathan Turley, who was invited by Republicans to testify during the impeachment proceedings.

“Even if Trump persuaded Congress to delay the election past that date, his term still constitutionally ends on that date unless he is reelected,” he wrote.

Trump’s repeated criticism of the voting process

As for Trump’s attempt to distinguish absentee from mail-in voting, that’s just spin, election experts have said.

“Different states use different words to refer to the same thing,” said Wendy Weiser, director of the Democracy Project at the Brennan Center for Justice at NYU Law School.

Trump’s tweet came before historically bad news about the economy during the COVID-19 pandemic. Trump is trailing Joe Biden in the polls, with the nation souring on his administration’s response.

Asked about Trump’s suggestion to delay the election, Trump campaign spokesman Hogan Gidley told other media outlets “the president is just raising a question about the chaos Democrats have created.”

Trump has repeatedly raised questions about the workings of the 2020 election, including primary contests where mail-in balloting was used widely. Trump suggested that mail-in ballots are rife with fraud, a falsehood. (Trump himself voted by mail in Florida’s presidential primary.)

As recently as three months ago, Trump dismissed the idea of changing the election date. At a press briefing on April 27, a reporter asked Trump about the warning by former Vice President Joe Biden — the presumptive Democratic nominee — that Trump was considering changing the date.

“I never even thought of changing the date of the election,” he said. “Why would I do that? November 3rd. It’s a good number. No, I look forward to that election.”

The Republican National Committee chairwoman, Ronna McDaniel, told Fox Business News that Trump understands that Congress sets the election but added that the president was trying to highlight the “huge problem right now with mail-in voting across the country.” She pointed to the weeks of counting ballots in the New York primary.

Other ways the election could be disrupted

There may be other ways for Trump to disrupt the election, experts said.

“Trump or state governors could seek to use public health concerns as a pretext to close polling places in Democratic cities in swing states,” Rick Hasen, an election law expert at the University of California-Irvine, wrote in an April op-ed in the Los Angeles Times.

Edward Foley, an election-law specialist at Ohio State University, said that Trump could theoretically issue an executive “stay at home” order, citing the coronavirus or civil unrest, that would prevent citizens from voting. “This would not change the date of the election as a matter of election law, but it would have electoral consequences that would need to be remedied,” Foley told PolitiFact.

If a state can’t hold an election on time, the state legislature can decide later how to appoint electors, the Congressional Research Service concluded. Hasen expressed concern that this could be a backdoor way to overturn the will of the voters.

This article was originally published by PolitiFact.