CHARLOTTE, N.C. — Taking the stage shortly after wrapping up the nomination for a second term, President Trump warned the Republican National Convention to watch out for the Democrats’ dirty tricks in the election.
He said the expected flood of mail-in voting would be ripe for manipulation, similar to what he described as misdeeds by the Obama administration during the 2016 race.
“They’re trying to steal the election, just like they did it last time with spying, and we caught them, and that included President Obama,” Mr. Trump said. “The only way they can take this election away from us if it is a rigged election.”
He called the push for more mail-in voting “the greatest scam in the history of politics.”
Mr. Trump has previously accused then-President Barack Obama and then-Vice President Joseph R. Biden, the Democratic 2020 nominee, of involvement in the FBI’s surveillance of his campaign in 2016.
Mr. Trump said the Democrats’ demands for widespread mail-in voting and attacks on the U.S. Postal Service were aimed at rigging the election and setting up a challenge of the results if Mr. Biden doesn’t win.
“You have to be very, very careful, and you have to watch everyone because bad things happened last time with this fine campaign and that goes to Biden and that goes to Obama,” Mr. Trump said. “And we have to be very, very careful.”
Mr. Obama and Mr. Biden have said they were not aware of the specifics of the FBI’s early Trump-Russia collusion investigation, which eventually morphed into the special counsel probe that dogged Mr. Trump for most of his first term in the White House.
Democrats used the allegations of collusion with Russia to claim Mr. Trump was an illegitimate president, though none of the numerous probes found evidence of a conspiracy.
Mr. Trump told the convention that this time, Democrats would use the post office to undermine the election results.
“This time they try to do with the whole post office scam,” he said. “They’ll blame it on the post office. You could see them setting it up. Be very careful and watch it very carefully, because we have to win. This is the most important election in the history of our country.”
• Alex Swoyer reported from Washington.