Nasty only from the commentators…….

Donald Trump and Ben Carson were put on the hot seat for their economic policies at a wonkish presidential debate Wednesday hosted by the business television network CNBC.

Trump and Carson, the two outsider candidates who have dominated the Republican race, were attacked out of the gate at the third prime-time bout by some of their competitors — and the CNBC hosts themselves.

CNBC moderator John Harwood asked Trump if he was running a “comic book” version of a White House candidacy while Ohio Gov. John Kasich argued Carson and Trump are not fit for the White House.

“My great concern is that we’re on the verge of picking someone who cannot do this job,” said Kasich, the first candidate to speak at the debate. “I’ve watched as someone said we should dismantle Medicaid and leave our senior citizens out in the cold. I’ve heard them talking about deporting 10 or 11 [million] people.”

Carson, a retired neurosurgeon, and Trump, a billionaire real estate mogul, stood side by side at center stage, the clear leaders in recent polls.

The two are well ahead of the rest of the field, and Kasich, former Florida Gov. Jeb Bush and Sen. Ted Cruz (R-Texas) all signaled they intended to make a move with Wednesday’s debate.

After his blistering opening statement, Kasich returned to his theme that Trump is not ready to be president by criticizing his immigration proposal.

“Folks, we’ve got to wake up. We cannot elect somebody who does not know the job,” Kasich said.

Trump shot back, focusing his barbs on energy in Ohio.

“John got lucky with a thing called fracking,” Trump said.

He then went after Kasich for being a managing partner at Lehman Brothers, the Wall Street investment bank that went bankrupt in 2008 and helped trigger the financial crisis.

“Lehman Brothers started it all, and he was a managing partner,” Trump said. “Then his poll numbers tanked. That is why he’s at the end [of the stage]. … So you know what? You can have him.”

Kasich didn’t relent.

“I wasn’t on the board of Lehman Brothers … I was a banker … and I traveled the country and learned how people created jobs,” Kasich said.

“My state is doing great across the board.”

Cruz, who hopes to win over supporters now backing Trump and Carson, highlighted his new flat tax proposal, which would impose a 10 percent flat tax on personal income and a 16 percent tax on businesses.

He also won cheers with a vigorous attack on the media in general, and the CNBC moderators in particular.

Cruz, asked about the debt limit, instead diverted to assert that the questions posed in the first half-hour of the debate “illustrate why the American people don’t trust the media. This is not a cage match.”

“How about talking about the substantive issues?” Cruz asked as wild applause nearly drowned out his words.