Donald Trump fired back at Mitt Romney in a big way on Thursday, claiming the former Republican presidential nominee “would have dropped to his knees” for the billionaire’s endorsement.

“I could have said ‘Mitt, drop to your knees’ and he would have dropped to his knees,” Trump told a crowd of supporters in Portland, Maine.

Romney deflected the comment during Trump’s speech.

If Trump had said 4 years ago the things he says today about the KKK, Muslims, Mexicans, disabled, I would NOT have accepted his endorsement — Mitt Romney (@MittRomney) March 3, 2016

Romney took Trump to task in a speech Thursday, calling Trump “a phony” who is “playing the American public for suckers” and issued a plea for fellow Republicans to shun the front-runner for the good of country and party.

Most suspected Trump to spend a healthy amount of time addressing the former Massachusetts governor’s comments and he didn’t disappoint, despite saying “I’ll just address (the comments) quickly because it’s irrelevant,” misquoting Romney several times and avoiding some of Romney’s main grievances.

Trump lashed out at Romney, saying “he doesn’t have what it takes to be president” and that Romney refused to run for the presidency again because he’s afraid of Trump.

“Mitt is a failed candidate,” Trump said. “He failed horribly.”

While he said he supported Romney because he dislikes Barack Obama so much, Trump labeled Romney a “choke artist” and a “disappointment” on more than one occasion.

“He choked and he choked like I’ve never seen anybody choke,” Trump said regarding Romney’s 2012 loss to Obama.

One of Romney’s main arguments against Trump was his economic policies.

“But wait, you say, isn’t he a huge business success that knows what he’s talking about? No he isn’t,” Romney said.

Trump countered with his history of leading construction projects in Manhattan and several other locations around the nation.

“He didn’t mention many of the many, many buildings,” he said. “We have 120 job (sites) all over the world.”

Trump also quickly brought up the issue of domestic trade — despite Romney not mentioning it in his Thursday speech.

“Nobody knows more about trade than me,” the billionaire said. “I’ve made a lot of money. I have a store that’s worth more money than Mitt.”

Romney zeroed in on Trump’s refusal to release his tax returns.

“He will never ever release his tax returns,” he said. “Never. Not the returns under audit, not even the returns that are no longer being audited. He has too much to hide.”

Trump has stuck to his argument that he cannot release his returns because he’s constantly being audited.

“I get audited every single year because my company is so big,” he said Thursday.

The Associated Press contributed to this report.

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