MESA, Arizona -- GOP frontrunner Donald Trump teed off on his Republican rivals at a post-debate rally in Mesa on Wednesday, and said Jeb Bush's approbation doesn't much matter to him.

"You know, I don't care if a guy like Jeb Bush never endorses me," Trump said. "It wouldn't bother me at all. I think it's a negative."

At Tuesday night's Republican debate, Bush and Trump clashed a number of times. Bush was more aggressive than in previous debates, and Trump lashed out at him, calling his campaign "a disaster" at one point. Bush told Trump he couldn't insult his way to the presidency. The billionaire also mocked Bush's poll numbers on stage Tuesday.

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"And then I hit back very, very hard. But look, we need strong people. We need sharp people. We are being killed. We are being beaten by everybody."

His supporters, unsurprisingly, were impressed by Trump's debate performance.

"I like his facial expressions when they rip on him," said 67-year-old Robert Stearns, a retired mechanic and Vietnam veteran from Apache Junction. "I think it's the usual rhetoric out of the other contenders. I think [Trump] always does okay. I don't think anybody that likes him thinks he's doing anything wrong."

The outdoor rally turned out thousands of supporters in forty-degree temperatures. Attendees started lining up at least four hours ahead of time. Trump landed with in his private jet with music from the soundtrack of "Air Force One" blaring over loudspeakers, while supporters craned their necks trying to get a picture of Trump coming off his jet.

Before Trump took the stage, controversial Arizona Sheriff Joe Arpaio reminded the crowd that he and Trump shared certain commonalities, such as "the birth certificate investigation." Arpaio was referring to the debunked implications by Trump in 2012 that President Barack Obama was not born in the United States, thus making him ineligible to hold the office of the presidency. Arpaio went on to say the investigation "is still going on."