Donald Trump, right, shushes Jeb Bush at the debate. ABC Real-estate mogul Donald Trump confronted a Republican debate audience that repeatedly booed him during an exchange with former Florida Gov. Jeb Bush (R).

Their sparring come over eminent domain — the power of the government to force people to sell their private property — which many conservatives have long criticized.

After Trump defended the general concept of eminent domain as a "necessity" for government, Bush jumped in with a specific critique of the developer's record on the topic.

"The difference between eminent domain for public purpose — as Donald said: roads and infrastructure and pipelines and all that, that's for public purpose — but what Donald Trump did was use eminent domain to try to take the property of an elderly woman on the strip in Atlantic City. That's not a public purpose. That is downright wrong."

This was a reference to Trump's attempted use of eminent domain in Atlantic City, New Jersey, during the 1990s, when the real-estate mogul was investing in the city's casino empire. The woman in question, Vera Coking, refused to sell her home and successfully fought the state's attempt to seize her land.

Sen. Ted Cruz (R-Texas), who defeated Trump in the Monday-night Iowa caucuses, also hit Trump on the eminent-domain issue in the lead-up to the Iowa vote.

On Saturday night, Bush attempted to continue ripping into Trump, but Trump started interrupting him.

"All right. OK. Jeb, Jeb — he wants to be a tough guy. He wants to be a tough guy tonight. I didn't take the property," Trump said, as he and Bush talked over each other.

When Trump got his formal allotment of time, he again mocked Bush for supposedly trying to look like a "tough guy."

"He wants to be a tough guy … and it doesn't work very well with him," Trump said.

Donald Trump. REUTERS/Carlo Allegri

It was then Bush's turn to interrupt. Bush asked how "tough" it was to try and take property from an elderly woman. Trump then shushed him.

"Let me talk. Let me talk. Quiet," he said.

The audience loudly booed Trump, driving the back-and-forth off the rails. Trump said audience members were all members of the Republican establishment.

"That's all of his donors and special interests out there," Trump said of the people booing him. "That's what it is. And by the way, let me just tell you: We needed tickets. You can't get them. You know who has the tickets? … Donors, special interests, the people that are putting up the money. That's who it is."

The booing continued. Trump said he was self-funding his campaign, so Republican donors weren't a fan of his candidacy.

"The reason they're not loving me is I don't want their money. I'm going to do the right thing for the American public," Trump said.

He was booed again shortly after.