The ad campaign, shared exclusively with NBC News, was paid for by the Article III Foundation, a dark-money group linked to Mike Davis, a controversial ally of Donald Trump. Voter registration deadlines are nearing, and early voting is beginning in states with sizable Latino populations, like Arizona, Nevada and Pennsylvania.

It is very rare for noncitizens to try to vote in elections; studies have found virtually no instances of it happening and no evidence that it could be occurring at a rate large enough to affect the outcome of an election. A study by the Brennan Center for Justice, a group focused on democracy, criminal justice, voting rights and other issues, which has been sharply critical of Trump’s claims of voter fraud, found that in 2016, officials referred to authorities 30 of 23.5 million votes in 42 jurisdictions as having been cast by possible noncitizens.