From one real estate mogul about another: Don't underestimate Republican presidential candidate Donald Trump, whose controversial remarks have turned the political world on its head.

"Americans are so fed up with scripted guys who don't sound authentic, [and] the country wants change," Barry Sternlicht, chairman and CEO of the $40 billion-plus investment firm Starwood Capital Group, said Thursday.

Pointing to what seemed to many people as a joke candidacy in Minnesota in the late 1990s, he said, "Jesse Ventura won the governorship" with his blunt, plainspoken campaign style.



Sternlicht told CNBC's "Squawk Box" that when Trump says, "I want to make this country great again," Americans completely believe him.

"It doesn't sound like some pollster gave it to him," the Starwood chief said. "America is ready to shake it up."

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Sternlicht, a Democratic voter in the past, did not endorse any candidate, but reiterated his past admiration for GOP hopeful Jeb Bush.

At the same time, he blasted Democratic presidential candidate Hillary Clinton for "hiding 55,000 emails," referring to the flap surrounding her use of a personal email account during her time as secretary of state.

"This would have been a great time for a third-party candidate. But you can't get into the system," said Sternlicht—adding Trump is like such a candidate.

"He may be his own party candidate. I don't know what party he's in. But he's in the Republican Party right now," Sternlicht said, jokingly.