Businessman Donald TrumpDonald TrumpUK vote triggers talks with US Clinton stretches lead over Trump to 14 points in national poll Aziz Ansari tells Trump to 'go f--- himself' over Muslim ban MORE took shots at the field of potential Republican presidential candidates and also fired one at House Speaker John BoehnerJohn BoehnerCameras go dark during House Democrats' sit-in Rubio flies with Obama on Air Force One to Orlando Juan Williams: The capitulation of Paul Ryan MORE (R-Ohio) as he contemplates a 2012 bid.
Trump said he could put up as much as $600 million of his own money in a race against President Obama, whose birthplace Trump said he doubts a little bit.
Former Massachusetts Gov. Mitt Romney "doesn't seem to resonate," Trump said on ABC's "Good Morning America," and former Minnesota Gov. Tim Pawlenty isn't going to "captivate the voters."
Of former Alaska Gov. Sarah Palin: "She did fine as the governor. I think, personally, she made a tragic mistake when she left early. I think she's more qualified than Barack ObamaBarack ObamaOur most toxic export: American politick State Dept. insists Brexit won't hurt relations with UK, EU WATCH LIVE: Obama speaks at roundtable with Zuckerberg MORE was, when he became president."
The reality TV star also made a tough assessment of Jon Huntsman, the former GOP governor of Utah, and Obama's ambassador to China: "When you work for somebody else, as he has worked for Barack Obama, you don't leave and then run against that person. It's very disloyal."
By comparison, Trump said he "like[s]" Gingrich, and thought that Huckabee was one of the few Republicans who could actually be successful.
"I really like him; he's the kind of a guy that maybe could really get some votes," Trump said of Huckabee.
The real estate mogul also expressed personal affection toward BoehnerJohn BoehnerCameras go dark during House Democrats' sit-in Rubio flies with Obama on Air Force One to Orlando Juan Williams: The capitulation of Paul Ryan MORE, but said he was offput by the Speaker's occasional crying.
"I don't like the crying. I do not like it. I don't understand it. I really like him as a person," Trump said. "I think the crying is an emotional thing that, frankly, probably makes him a very nice man. But, you know, I don't like to see it in a leader."
Trump's flirted in the past with running for president, and maintains that he's more serious now than ever. Still, his potential candidacy -- he says he'll decide whether to run in June -- has drawn guffaws so far among professional Republicans.
He said he's "absolutely" willing to commit as much as $600 million of his own money to the race, if he's doing well.
"Part of the beauty of me is that I'm very rich," Trump explained.
And Trump even made a pitch to "birthers," the faction within the GOP who incorrectly assert that Obama was born outside the United States, and is therefore constitutionally ineligible to be president.
"Everybody who gives even a hint of being a birther ... even a little bit of a hint ... they label them as an idiot," Trump said. "Let me tell you, I'm a really smart guy. The reason I have a little doubt -- just a little -- is because he grew up, and nobody knew him."