Former Republican Massachusetts Gov. Bill Weld this morning said he would have to see Donald Trump “settle down” and “evolve” before he could support the celebrity billionaire in the general election — and defended Democrat Hillary Clinton on her ongoing private email server controversy.

“I’ve never bought that email thing,” said Weld, who was the U.S. attorney for Massachusetts in the 1980s and ran the Department of Justice Criminal Division for two years under President Reagan, when asked if the email furor could stop him from potentially backing Clinton in the fall. “I don’t think anything was classified when she, when she did it — it got classified later. So, it’s probably because I’ve not been professionally involved in analyzing that case. And I know her well, and you know, I don’t think she would lay a lot of stuff out on the table. So, I’m not a buyer.”

Weld, who lived in New York for years after serving as Massachusetts governor, said he knows both Trump and Clinton — and would have to see some changes before he backs the GOP frontrunner.

“You know, if he settles down, yeah,” said Weld, who is backing Ohio Gov. John Kasich in the GOP primary, when asked on Boston Herald Radio whether he would support Trump in the fall. “But I also have a long relationship with Mrs. Clinton, Hillary Clinton…so, I’d want to see how the campaign unfolds there, or…which is a way of saying how Donald Trump evolves as a candidate, and I know it’s Howie Carr’s least favorite word, but I think something like that is going to be required.”

He added: “I’m not a member of the Stop Trump at all Costs Brigade. I think it really…it depends on whether Donald dials it down a little bit, you know, at the beginning, he was really X-rated, and my sense he’s…he may have tamped it down a little bit in the last month or so. Although, you know, the last week or so, not so much.”

Weld said he knew Trump “ socially” in New York and suspects his campaign persona does not reflect his true, more liberal views — and more measured demeanor.

“He’s a different guy there, he’s calm, you know…so, a lot of this, a lot of this boo-hah-hah that you see now is for the election,” Weld said. “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, it’s not all bad. … You know, I thought early in the campaign, he said ‘heck, I’m from New York, of course I’m pro-choice,’ which doesn’t bother me, because I’m on that side, on the social issues. And I think he’s dialed that one way back recently. So, that would, that would, that would give you some cause as to which is the real answer. … I’m a fiscal conservative, social moderate, so that doesn’t bother me. I just wish he came right out and said it, but he keeps saying the opposite now.”

The former governor has worked as an international business consultant for law firms in Washington, D.C., and New York since leaving office, and is again one of the state’s biggest powerbrokers as a principal at ML Strategies. He said he regards Trump as a “very good” negotiator — but noted the real estate magnate’s business reputation also is marred by bankruptcies.

“Donald can make deals. So, that part is absolutely true,” Weld said. “You know, I think the one area of concern is that there have been a lot of small bankruptcies that have dogged his businesses and sometimes, you know, he’ll insist on a deal being recut, or else his special purpose vehicle that did the deal is going to have to declare bankruptcy, and that’s not a good pattern. You know, it’s maybe not illegal, each individual case, but that’s the only kind of spot on the record. But in terms of being smart and being able to negotiate, yes, Donald is very good, very good.”

Weld says he is backing Kasich — who he compared to former Bay State Democratic Sen. Edward M. Kennedy — even as he lags in the polls nationwide.

“You know, if you listen to him in these debates, he really knows what he’s talking about,” Weld said. “He’s one of these guys, that in a way…Ted Kennedy, I always liked him, he knew his heart was connected to his head. I have the same feeling about Kasich. He’s not making stuff up, it’s coming from, from the gut, and I think of him as not quite a lone wolf, but somebody who figures everything out himself and then goes for it, which is a very good quality in a president of the United States.”