Gregory Korte

USA TODAY

WASHINGTON — Billionaire industrialist Charles Koch, whose political spending has fueled libertarian causes and conservative candidates for decades, said Sunday that it's "possible" Democrat Hillary Clinton would make a better president than the Republican nominee.

He quickly qualified that in order to support her, "we would have to believe her actions would be quite different than her rhetoric." But he said that's no different from some of the Republican candidates whose rhetoric he criticized.

In an interview with ABC's Jonathan Karl that aired Sunday, Koch was also highly critical of Donald Trump's campaign, even if he hasn't contributed to the "Stop Trump" movement.

One concern: Trump's campaign promise to deport Muslims. "What was worse was this, 'We'll have them all register,' " Koch said. "That's reminiscent of Nazi Germany. I mean, that's monstrous."

He also criticized Sen. Ted Cruz's pledge to "carpet bomb" Syria. Though he said Cruz was likely engaging in hyperbole to appeal to voters, he called the prospect "frightening."

Though Koch's political spending benefits Republican candidates, he's long made clear he adheres more to limited-government principles than the establishment party platform. And he's sometimes praised Democratic presidents and criticized Republican ones, saying in some ways Bill Clinton was a better president that George W. Bush.

"I mean, he wasn't an exemplar," Koch said. "But as far as the growth of government, the increase in spending, on restrictive regulations, it was two and half times under Bush than it was under Clinton."

Koch has also been critical of Bush's war spending. Bush, he said, "is a fine person and tried to do the right thing but was misguided."