Possibly taking inspiration from Tommy DeVito, Joe Pesci’s character in the movie Goodfellas, J.D. Vance, a Republican running for U.S. Senate, said: “You’ve got to be yourself. I think that’s one of the mistakes, by the way, that a lot of these clowns have made in the primary where they haven’t learned anything from the substance of how (Donald) Trump governed. They try to act like Trump, but you’re not Trump.”

Apparently the other Republicans running for the U.S. Senate nomination in Ohio amuse him.

They likely feel the same about Vance, who has been accused of shape-shifting — going from a Trump critic to the former president’s endorsed candidate.

Josh Mandel, a former state treasurer and another GOP Senate candidate, called Vance a “never Trumper” at an event last week in Cortland.

Also, Jane Timken, a former Ohio Republican Party chairwoman and Senate candidate, said last week in Boardman: “J.D. was an avowed never Trumper. If he had his way, Hillary Clinton would have been president, but Ohio voters are smart, and they’ll see right through that.”

But since the former president endorsed Vance two weeks ago, the author and venture capitalist has gone from the middle of the pack to frontrunner status in the Senate race in Ohio.

The Republican primary always has been about Trump.

Five candidates ran on a platform of being most in tune with Trump.

Bernie Moreno, one of them, got out of the race in February after meeting with the former president who was concerned there were too many pro-Trump candidates seeking the Republican nomination.

That left Mandel, Timken, Vance and investment banker Mike Gibbons to fight it out for Trump’s support.

Trump’s decision two weeks ago to endorse Vance was a huge boost to his campaign and devastating setbacks for Mandel, Gibbons and Timken.

Vance hasn’t been terribly gracious.

During his Wednesday stop at the Mahoning County Republican Party headquarters, not only did he call his GOP challengers “clowns,” but he took a shot at Timken, who had an event last week in Boardman, saying she “didn’t have the same crowd (size) — not to rub it in.”

Of course, he was rubbing it in. Before getting Trump’s endorsement, Vance wasn’t drawing the crowds he is now.

As a celebrity before he was president, Trump has attached himself to other celebrity first-time candidates such as Dr. Mehmet Oz in the Pennsylvania Senate race and former football star Herschel Walker in Georgia’s Senate race.

Polls taken before Trump’s endorsement showed a two-person race between Mandel and Gibbons.

The influence Trump has over the Republican Party has resulted in Vance looking like the candidate to beat in Tuesday’s primary.

Some local Republicans who were solidly behind other candidates now are backing Vance because of Trump’s endorsement.

There’s been backlash from some Republicans to Trump’s endorsement of Vance, who was critical of him during the 2016 presidential campaign and acknowledged he didn’t vote for him. During this campaign, Vance said he was wrong about Trump.

At a rally last week in Delaware County, Trump acknowledged the criticism saying Vance had “said some bad s–” about him.

“But you know what? Every one of the others did also,” Trump said. “In fact, if I went by that standard, I don’t think I would’ve ever endorsed anybody in the country.”

Trump added about Vance: “I like a lot of the other people in the race. I liked them a lot. But we have to pick the one that’s going to win. This guy is tough as hell. He’s going to win.”

Without Trump’s endorsement, Vance had little chance of winning. This is a real test of Trump’s power.

Though Mandel and Timken didn’t get Trump’s endorsement, they spent a lot of time talking positively about him and his agenda during local campaign stops last week.

Mandel repeated unproven claims by Trump that the 2020 election was “stolen” from him and called for an audit of state voting results, including Ohio, where Trump won by 8 percent.

Vance also agreed the election was “stolen” from Trump.

Trump and his allies lost more than 60 court challenges to the 2020 presidential election results.