Donald Trump on Monday claimed without proof that foreign countries would try to influence the 2020 elections by printing mail-in ballots, his latest lie in long list of attempts to delegitimize safer voting.

"RIGGED 2020 ELECTION: MILLIONS OF MAIL-IN BALLOTS WILL BE PRINTED BY FOREIGN COUNTRIES, AND OTHERS. IT WILL BE THE SCANDAL OF OUR TIMES!" Trump tweeted in all capital letters Monday morning.

Trump's claim builds on remarks by Attorney General William Barr, who also pushed the false conspiracy theory earlier this month.Election experts say it's almost impossible for foreign countries to print counterfeit ballots.

"This would be a waste of paper," Michael McDonald, a professor at the University of Florida who studies elections, tweeted. "The legally valid ones printed by election officials have many safeguards to protect against fraudulent voting."

Those safeguards include signature matching against voter records, which would make printing and mailing in counterfeit ballots nearly impossible, as well as things like mandatory notarization in some states.

Each of the nearly 175,000 voting precincts in the country also have their own unique ballots that contain different local elections and ballot questions, meaning foreign countries would have to perfectly replicate each one in order to successfully submit fraudulent ballots.

Voting by mail is popular in the United States. Trump, along with a number of members of his inner circle, have voted by mail in the past.

Both Democrats and Republicans have sought to increase the number of people voting by mail in the wake of the coronavirus pandemic. Increasing vote-by-mail would prevent voters from having to wait in lines and risk transmitting the virus to cast their ballot.

Trump is firmly against the idea. He has admitted that he doesn't support increased access to voting by mail because he feels it will make casting a ballot easier, and that more people voting will hurt his reelection chances.

There is no evidence that vote-by-mail benefits one party over another.

Democrats believe Trump's attack on mail-in voting is a sign he may not go quietly if he loses in November.

"It's my greatest concern, my single greatest concern: This president is going to steal this election," presumptive Democratic presidential nominee Joe Biden toldThe Daily Show host Trevor Noah on June 12.

"This is a guy who said all mail-in ballots are fraudulent, direct voting by mail, while he sits behind a desk in the Oval Office and writes his mail-in ballot to vote in the primary."

Published with permission of The American Independent Foundation.