Libertarian vice presidential candidate Bill Weld yesterday called Republican Donald Trump a “malignant narcissist” unfit to be president.

“You want someone who is calm,” the former Bay State governor said, referencing Trump’s habit of barraging foes with vicious tweets. “When you are governor or chief executive of a government, you make a hundred decisions a day and you get judged at the end of the year by how you did. If you have to stop and think how can I take a swipe at someone in this situation, that is the last thing you want in a president of the United States.”

Weld is running on the Libertarian ticket with former New Mexico Gov. Gary Johnson, and has said he was motivated in part by his distaste for Trump’s views on immigration.

Speaking on Herald Radio yesterday, Weld said of Trump, “In psychology, it’s called a malignant narcissist: someone who’s not happy succeeding unless everyone else fails at the same time.”

He added: “Unfortunately, you could say that that happened a little bit with Mr. Trump’s success with his casinos in Atlantic City because hundreds if not thousands of small businesses went down the tubes when Mr. Trump was rising there.”

In March, Weld told Herald Radio the Trump he knew socially when he lived in New York was “a different guy.”

“He’s, you know, he’s a pleasant guy, he’s a generous guy, very nice wife, Melania, he’s been good to his kids. It’s not all bad,” he said at the time, adding he could support Trump in the general election “if he settles down.”

Since then, the two have traded blows, with Weld comparing Trump’s anti-immigration plan to Kristallnacht — the violent 1938 Nazi attacks on Jewish homes, businesses, schools and synagogues — and Trump responding by calling Weld an alcoholic.

Weld and Johnson are seeking to reach a 15 percent threshold in the polls, which could get them on the national debate stage and help get endorsements from Republican holdouts including former Gov. Mitt Romney, Gov. John Kasich or Sen. Ted Cruz.

“I’m in touch with some of them. I’m not pressing the hard sell for a little bit longer. I think it would be good if Gary Johnson and I get to 15 percent, so we would presumptively be in the debates,” Weld said. “I’ve had some conversations with Mitt, and that’s still baking.”

A recent national poll measuring has the Johnson/Weld ticket at 9 percent.

“We know how to get the job done, and I think in the fullness of time a number of people will come around,” Weld said.