President Trump is urging Republicans to vote in South Carolina’s Democratic primary on Saturday for the weakest candidate — determining that is Vermont Sen. Bernie Sanders.

Trump, hosting a rally in South Carolina on Friday night, asked his crowd to help him pick the recipient of GOP votes in the “open” primary.

“I assume this is okay from a campaign finance standpoint,” Trump joked before carrying out his “poll” on the eve of the primary election.

He asked audience members to cheer for the Democrat they’d prefer be his easiest-to-beat opponent — Sanders or former Vice President Joe Biden.

“I think maybe Crazy Bernie has it,” Trump said.

Asking one more time for his supporters to cheer for either former vice president Biden or Sanders, Trump confirmed: “They think Bernie’s easier to beat.”

Sanders, a self-declared socialist, emerged as the front-runner after popular-vote wins in Iowa, New Hampshire, and Nevada. His potential nomination terrifies many Democrats, who fear a Trump landslide.

Biden leads Sanders in South Carolina polls ahead of Saturday voting, but Republicans could swing the outcome and give Sanders momentum ahead of the 14-state Super Tuesday contests next week.

“Really, we’re down to two candidates, right? Sleepy Joe Biden and Crazy Bernie,” Trump said. “So this is a poll. I guarantee you this, as much as they hate me… they’re gonna put this all over the place. We have a poll of like 30,000 people.”

Trump belittled Democrats running for president, saying that former New York City Mayor Mike Bloomberg “wishes he never started.”

“Should we include Mini Mike or not?” Trump asked the audience. “Nooooo!” they responded.

“Mini Mike is gone. I think he’s gone. He doesn’t have a chance,” Trump said. “I hear Mini Mike, by the way, has left. He’s basically given up, that’s what I hear. He gave up. He gave up. I hope what I said keeps him in.”

Trump omitted from his bash-spree former South Bend, Indiana, Mayor Pete Buttigieg, who won the most delegates in Iowa and placed second in New Hampshire.

Trump dismissed outright fellow billionaire Tom Steyer as a “loser” who is “not that wealthy” and said Sen. Elizabeth Warren of Massachusetts is “so damn mean.”

Trump’s urging echoes past attempts by conservatives to cross lines en masse to influence Democratic politics, most significantly radio host Rush Limbaugh’s “operation chaos” in 2008 to extend the primary clash between Barack Obama and Hillary Clinton.