Former President Trump savaged Vice President Harris as “mentally impaired” as he took the border “czar” to task during a long and graphic campaign stemwinder in Wisconsin on Saturday.

“Joe Biden became mentally impaired. Kamala was born that way … only a mentally disabled person could have allowed this to happen to our country,” Trump, 78, said to raucous applause during remarks in Prairie du Chien.

She’s a “very dumb person,” Trump added later on.

The speech was focused primarily on immigration, long a cornerstone of Trump’s campaign. During his remarks, the former president offered graphic stories of a nation he said had been overrun by illegal migrants.

“Just this month, right here in this beautiful town, police arrested an illegal alien, member of a savage Venezuelan prison gang,” Trump said.

“This vile monster was charged with holding a mother and daughter captive against their will and sexually assaulting them again and again. This animal crossed Kamala’s wide-open border, along with hundreds of thousands of others that are worse than him.”

Alejandro Jose Coronel Zarate, 26, is accused of sexually and physically assaulting a woman “under particularly brutal circumstances” and holding her and her minor daughter against their will.

Harris is “letting in people who are going to walk into your house, break [through] your door, and they’ll do anything they want. They’ll do anything they want. These people are animals,” Trump continued.

“They make our criminals look like babies. These are stone-cold killers. They’ll walk into your kitchen. They’ll cut your throat.”

Swing state polling shows deep pessimism among the electorate with upwards of four in 10 Wisconsin voters saying the nation is at risk of becoming a failed state.

At various points, Trump digressed into other favorite subjects.

He told the assembled crowd he had lawyered up for the 2024 presidential election and was prepared to dole out punishment to anyone caught trying to subvert the result, should he be elected.

“If we win and when we win, we’re going to prosecute people that cheat on this election,” he said. “And if we can, we’ll go back to the last one, too … You need two things, strong borders and fair elections. And we have neither.”

Trump also accused Harris of planning to legalize deadly fentanyl in the United States.

“She’s so radical, she even wants to legalize fentanyl right away. Fentanyl will kill you just a little tiny on the top of a pin,” Trump said. “I have so many friends that have lost their children to fentanyl.”

The candidate also digressed briefly into the troubles of New York Mayor Eric Adams, who was hit with a slew of federal charges this week, including bribery, wire fraud and conspiracy. Echoing comments he made at Trump Tower, Trump said Adams never would have faced the federal hammer if he had kept his mouth shut about the migrant crisis in the Big Apple.

“[Migrants] all over the place. And I’m telling you what I said before, these towns, these little towns and cities, and by the way, the big cities too. New York, look what’s happened in New York. And they went after the mayor of New York because he was saying, we can’t do this. We can’t do that. They just indicted him,” Trump said — calling Adams pursuers “vicious monsters in our government.”

Earlier Saturday Trump’s running mate Sen. JD Vance also made remarks on immigration in which he promised a “compassionate” border policy.