Republican presidential nominee former President Donald Trump dances at a campaign rally at Bayfront Convention Center in Erie, Pa., Sunday, Sept. 29, 2024. (AP Photo/Rebecca Droke)

ERIE, Pa. (AP) — Republican presidential nominee Donald Trump escalated his personal attacks on his Democratic rival, Kamala Harris, on Sunday by repeating an insult that she was “mentally impaired” while also saying she should be “impeached and prosecuted.”

Trump’s rally in Erie, Pennsylvania, took on similar themes as an event one day earlier that he described himself as a “dark speech.” He told a cheering crowd that Harris was responsible for an “invasion” at the U.S.-Mexico border and “she should be impeached and prosecuted for her actions.”

“Crooked Joe Biden became mentally impaired,” he added. “Sad. But lying Kamala Harris, honestly, I believe she was born that way. There’s something wrong with Kamala. And I just don’t know what it is but there is definitely something missing. And you know what, everybody knows it.”

With just over a month until the election, Trump is intensifying his use of personal and offensive attacks, even as some Republicans say he’d be better sticking to the issues.

His suggestions that political enemies be prosecuted are particularly notable for their departure from norms in the U.S. in which the justice system is supposed to be protected from political influence. In recent weeks, he has threatened prosecutions of Google for allegedly giving priority to “good stories” about Harris, Meta CEO Mark Zuckerberg, and anyone he deems to be “involved in unscrupulous behavior” related to the coming election.

Trump has long threatened legal action against his rivals, including President Joe Biden and his 2016 rival, Hillary Clinton. This month he threatened to jail those “involved in unscrupulous behavior” this election, including election workers, lawyers, political operatives, donors, and voters, yet again sowing doubt about the integrity of the election, even though fraud is very rare.

But he also has many legal problems of his own. He was convicted in May of falsifying business records in a hush money case in New York, with a sentencing scheduled for Nov. 26. Three other cases are pending against him, including one tossed out by a federal judge following a Supreme Court ruling granting presidents broad immunity. The Justice Department is appealing. The other cases are on hold.

If he wins the election, he could potentially pardon himself or order the Justice Department to shut the federal investigations against him.

On Sunday, he acknowledged he might lose in November: “If she wins, it’s not going to be so pleasant for me, but I don’t care.”

His derision of the first Black woman and person of South Asian descent to lead a major party ticket as “stupid,” “weak,” “dumb as a rock” and “lazy” is also a sign of how nasty and personal the final stretch of the campaign may be.

His allies have pushed him publicly and privately to talk instead about the economy, immigration and other issues.

“I just think the better course to take is to prosecute the case that her policies are destroying the country,” said Sen. Lindsey Graham, R-S.C., on CNN’s “State of the Union” Sunday when asked about Trump’s comments. “They’re crazy liberal.”