CHARLOTTE, N.C. (AP) — President Donald Trump has turned a surprise opening-day appearance at his party’s scaled-down national political convention into an opportunity to cast doubt on the integrity of the fall election.

That was just moments after delegates nominated him for a second term.

Trump vigorously contended that he’s done such a great job as president that the only way he can lose “is if this is a rigged election.”

He assailed anew the idea of mass mail-in voting by people worried about the coronavirus.

All the Radical Left Democrats are trying to do with the Post Office hearings is blame the Republicans for the FRAUD that will occur because of the 51 Million Ballots that are being sent to people who have not even requested them. They are setting the table for a BIG MESS!

— Donald J. Trump (@realDonaldTrump) August 24, 2020

Next: the convention moves to Washington for prime-time programming that will be a crucial moment for Trump, who is trailing in national and battleground state polls.

President Trump: “This is the most important election in the history of our country. Don’t let them take it away from you.

Full #RNC2020 video here: https://t.co/ZpNptJvTzQ pic.twitter.com/XilBoul7RO

— CSPAN (@cspan) August 24, 2020