Trump has no authority to deploy local law enforcement officials to monitor elections, although his campaign could hire off-duty police to work the polls, said Rick Hasen, an election law expert at the University of California at Irvine.

If Trump did so, it likely would trigger legal action from Democrats, who would claim the move amounted to a voter-suppression tactic. And it would have echoes of a case that resulted in a federal court decree that for decades sharply restricted the Republican National Committee’s “ballot security” work without prior judicial approval.

The 1982 decree arose from a Democratic National Committee lawsuit that accused the RNC of trying to suppress votes in New Jersey by, among other things, posting armed, off-duty police officers at the polls in Black and Latino neighborhoods. The decree expired in 2018, and this election marks the first presidential contest since 1980 that the GOP presidential nominee and the RNC will work together on poll-watching.