In an appearance on CNBC's "Squawk on the Street," Rensi said the president isn't a "political animal." Instead, Trump is a businessman who is interested in the well-being of Americans, Rensi contended.
"[Trump] doesn't like politics at all," said Rensi, who is now a food service and restaurant consultant. "He doesn't really care much for Democrats or Republicans. He's very interested in the American people."
Trump's got it "figured out" on tax reform, Rensi said. "We've got to get this corporate tax rate down," Rensi said. "We're at a huge disadvantage. Our American citizens need more money. We need more disposable income for people to be able to buy things."
The Affordable Care Act, better known as Obamacare, is a "disaster," Rensi added, and the nation's infrastructure and borders need work too.
Earlier Tuesday, Trump got into another social media feud with Sen. Bob Corker, amid the Republican push for an overhaul of the U.S. tax code.
"I don't like the fact that he's so inarticulate so often, but he's got the right strategic ideas," Rensi said. "Listen to his strategy. Ignore his idiot tweets."
Earlier this year, Rensi warned that Trump will become "irrelevant" if he doesn't change his ways and embrace leading. That came after the violent white supremacist rally in Charlottesville, Virginia. Rensi called Trump's response to the event "unacceptable."
Rensi spoke after McDonald's reported before the bell better-than-expected sales for its third-quarter. The stock was up around 2 percent on Tuesday.