Trump, Jeb Bush clash over George W. Bush

The months-long feud between Jeb Bush and Donald Trump has moved well beyond simple clashes over policy. At Saturday night's South Carolina debate, it again took on a very personal dimension.

CBS moderator John Dickerson asked Trump whether he still believed, as he expressed during a 2008 interview, that President George W. Bush should have been impeached over the Iraq War.

Trump began by saying that he gets "along with everybody" and noted he was a "self funder" amid boos from the crowd, which he'd cast as interest groups supporting Jeb Bush.

“Obviously the war in Iraq was a big fat mistake," Trump said.

He then criticized Jeb Bush's response earlier in the campaign on Iraq. “It took him five days before his people told him what to say," about whether it was the right decision to invade.

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When asked again whether he still thought the 43rd president should have been impeached, he said: “You call it whatever you want," adding that officials in the Bush administration had "lied."

Jeb Bush countered that he "could care less" about Trump's insults of him but that he was "sick and tired” of the billionaire's jabs against his family.

He added that while Trump was focused on creating a reality television show, “my brother was building a security apparatus to keep us safe." That prompted Trump to interject that the Sept. 11, 2001, attacks had occurred while George W. Bush was in office.

Ohio Gov. John Kasich tried to lighten the tone a bit.

“I gotta tell you, this is just crazy," he said.

Florida Sen. Marco Rubio, who hasn't exactly been a frequent ally of Jeb Bush in recent months, joined with the former Florida governor in arguing that President Bush had kept the nation safe, which again led to Trump saying "the World Trade center came down" during Bush's presidency.

Jeb Bush closed the fierce exchange by noting that he was "rescinding the invitation" for Trump to attend a rally with he and his brother on Monday.