Nikki Haley torched whatever was left of her political ambitions: MSNBC's Heilemann

Nikki Haley just destroyed her credibility and her political future with her "craven and cynical" endorsement of Donald Trump.

Toward the end of her own primary campaign, the former South Carolina governor became a vehement critic of the ex-president for whom she had served as United Nations ambassador, and while she still draws a sizable portion of the anti-Trump vote despite dropping out the race, she threw her support behind the presumptive GOP nominee.

"As you know, I was out there [on the campaign trail]," Heilemann told "Morning Joe." "I listened to her as she got tougher and tougher on Trump, from Iowa to New Hampshire, South Carolina. I went to a bunch of the events, listened to her get closer and closer to the edge. She wasn't making critiques of Trump on policy, primarily, she was saying things like, 'I've been in the room with Donald Trump and Vladimir Putin,' you know, and coming close to saying, you know, that he's not fit, competent to serve."

Haley justified her endorsement, despite her strong personal criticism of Trump, by citing his positions on foreign policy, immigration and the economy, saying that president Joe Biden “has been a catastrophe," and Heilemann said that should shred her credibility forever.

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"She came right up to the edge of making the critiques that never-Trump, that progressive Democrats and never-Trump Republicans have made," Heilemann added. "Those are existential arguments, those are not about any policy. They're about, this man is not fit to serve, this man is a threat to democracy – all of that, she was right in that zone. Then to retreat to policy is so craven and cynical. I think, what we have learned about her, the most cynical, the most negative critical people about Nikki Haley have always said, she is ambition incarnate – you cannot believe a word out of her mouth. She'll say whatever, and change her mind from Monday to Wednesday, Wednesday to Thursday. People were saying, you're been misogynist about it, you don't hold men to those standards. Some of us bent over backwards in this winter period to say, maybe she has finally come to Jesus here, she's not going to go back, she'll stake her claim. The theory that Trump loses this fall, she can say, 'I was right all along.'"

"I want to say here that, A., we should never believe a word she says about anything ever again, and, B., she must not be allowed by Republican voters who continue to go to the polls – she's still getting 20 percent of the vote," Heilemann added. "This month, now there's still 20 percent of Republicans in the primaries still voting for her. They must not let her in November – let me just say, what they can't let her do is, if Trump loses in November, stand up and say, 'Oh, I told you so.' She forfeits the right to say, 'I told you so, and I was always against Donald Trump.' She's now back on the Trump train, and there has got to be some accountability for that politically going forward."

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