Donald Trump, 2016 Republican presidential nominee, speaks during a campaign rally at the Erie Insurance Arena in Erie, Pennsylvania, U.S., on Friday, Aug. 12, 2016. Two days after Trump said that President Barack Obama had founded Islamic State, and a day after he insisted that he meant what he said, the Republican presidential nominee reversed himself on Friday and claimed the statement was nothing more than sarcasm. Photographer: Ty Wright/Bloomberg via Getty Images

Donald Trump’s presidential campaign is actively recruiting voters to volunteer as “election observers” at the polls this November, doubling down on the nominee’s claims the general election will be rigged despite the extreme rarity of voter fraud.

At a rally in Altoona, Pennsylvania, on Friday, Trump claimed Democratic nominee Hillary Clinton (whom polls show with a strong lead in the state) will only win it “if cheating goes on.” He also encouraged supporters to monitor the polls themselves.

“Go down to certain areas to and watch and study and make sure other people don’t come in and vote five times,” he said.

A form asking voters to help Trump “Stop Crooked Hillary From Rigging This Election!” appeared on his website Friday evening, as Politico reported:

After filling out the form, volunteers are directed to a donation page. They also receive the following email from the Trump team:

While regulations vary from state to state, campaigns are typically permitted to have election observers at polling sites to oversee voting. However, most states strictly prohibit soliciting votes or electioneering at polling places, and voter intimidation is illegal at the federal level.

Trump’s recruitment of election observers could also violate a decree that prevents the Republican National Committee from actively confronting voters, as Rick Hasen of Election Law Blog points out. Given the history of violence at Trump’s rallies ― and his tendency to encourage it ― it’s not hard to imagine his supporters getting confrontational at polling places.

As Trump’s standing in pre-election polling has dropped, he has repeatedly claimed the election will be “rigged” in Clinton’s favor. He’s also stoked fears of cheating at the polls, arguing that fraud will increase this year because courts have rolled back voter ID laws in some states.

Voter fraud, however, is extremely rare, and voter ID laws like the ones struck down in Texas and North Carolina were found to be racially discriminatory.

Pennsylvania’s own voter ID law was struck down in 2014 after a court found it would potentially disenfranchise hundreds of thousands of voters and would have a disproportionate impact on people with disabilities, the elderly and low-income voters.