As the Democratic presidential candidates targeted debate stage newcomer Michael Bloomberg in a ferocious clash over who will get to challenge President Trump in November, the president on Wednesday night stoked his base in a raucous "Keep America Great" rally in Phoenix -- before joining the attacks on the former New York City mayor.

To loud cheers in a crowded venue filled with red hats and campaign signs, Trump railed against previous FBI leadership as "dirty cops," touted his signing of the USMCA as a victory for farmers, called the media "fake news," bragged about killing terrorists and crowed over his success appointing federal judges and Supreme Court justices.

Later in the evening, Trump joined the chorus of attacks against Bloomberg, who has spent over $400 million on his campaign, over how the Democrat performed in the biggest moment of his quest for the White House so far.

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"Mini Mike Bloomberg’s debate performance tonight was perhaps the worst in the history of debates, and there have been some really bad ones," Trump tweeted. "He was stumbling, bumbling and grossly incompetent. If this doesn’t knock him out of the race, nothing will. Not so easy to do what I did!"

Meanwhile in Las Vegas, Democrats were going after each other for everything from non-disclosure agreements to their health care plans.

In an explosive moment, attendees cheered when Sen. Elizabeth Warren, D-Mass., called on Bloomberg to release women from nondisclosure agreements they have signed concerning their civil complaints that he harassed them in the workplace.

"Mr. Mayor, are you willing to release all of those women from those nondisclosure agreements, so we can hear their side of the story?" Warren asked, to thunderous applause.

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"We have very few nondisclosure agreements," Bloomberg responded. "None of them accused me of doing anything — except, maybe they didn't like a joke I told." The audience then booed loudly. Bloomberg refused multiple times to agree to release the women from the nondisclosure agreements, even as former Vice President Joe Biden explained that all Bloomberg has to do is give the word.

Warren landed one of the biggest punches of the night on the topic after Bloomberg cited gender diversity at his companies and his foundation to bolster his progressive credentials.

"I hope you heard what his defense was: 'I've been nice to some women,'" she said

Democrats also challenged Bloomberg on the "stop-and-frisk" policy from his tenure as New York City mayor, the fact he has not released his tax returns, his immense wealth and more.

Back in Phoenix, Trump took the opportunity to share his opinion on Bloomberg in front of his supporters, who he said under his presidency were no longer "deplorables."

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"Now they have a new member of the crew, Mini Mike," Trump said. "No boxes, we call him 'no boxes.' And I hear he's getting pounded tonight. You know he's in a debate? I hear they're pounding him.

"He spent $500 million so far," Trump said, only slightly exaggerating Bloomberg's campaign spending, "And I think he has 15 points. It just came out. Hey fake news, how many points does he have right now? 15?"

Trump also compared himself favorably to various other self-funded presidential campaigns, including Bloomberg's.

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"They had an article this weekend about people that spent their own money, and how they're doing," Trump said. "And they have Mini Mike has spent $411 million, and it's a question mark how he's gonna do. I'll tell you how he's gonna do. He's probably not going to get the Democratic nomination, that's how he's gonna do."

He continued: "But Mini Mike, $411 [million], then they had this idiot [Tom] Steyer, we call him 'impeachment Steyer.' How did that work out, Steyer? He's another beauty. The guy worked, he spent $210 million, he got one-third of one percent in Iowa, and in New Hampshire, he did much better. He got less than 3 percent. The guy's in there for like $250 million. How did it work out, Steyer? Jerk. I don't, I never even heard of him."

Trump also listed off former independent presidential candidate Ross Perot and former Republican primary candidate Steve Forbes before getting to his own campaign.

"In the middle they had Trump, and then they had four or five that were behind me, lot of money spent. Loss. Loss. Loss. Loss. Loss," Trump said. "But in the middle they have Donald Trump, and it didn't say $500 million and it didn't say 250 like this Steyer guy. It didn't say — it said $70 million, of my own money. I spent 70. And it said, 'Donald Trump won the presidency of the United States.'"

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The crowd broke out into loud cheers as Trump delivered the line.

"We won," Trump repeated.

Fox News' Gregg Re contributed to this report.