And just like that one of Hillary Clinton's biggest supporters, Warren Buffett, has flipped and after predicting doom under Trump, now expects prosperity for the US under America's new president.

In an interview with CNBC, the Omaha billionaire, said that "America works" and added that "It'll work wonderfully under Hillary Clinton, and I think it'll work fine under Donald Trump." The reason for his optimism: Buffett told CNBC the United States has the "secret sauce."

"It doesn't work all the time perfectly," the billionaire said, "but you just look at where we go, milestone after milestone. Never bet against America." With that mantra as a guiding principle, Buffett said, "we're almost always a buyer of stocks over time."

Focusing more on the stock market, Buffett reverted to his infamous optimism and reiterated his call to invest for the long haul; he acknowledged that he doesn't know where the stock market will go in the next "10 days or a year or two years." But he is confident that "It's going to be higher 10 years, 20 years from now."

"There will be hiccups from time to time in the economy," he cautioned. "[But] we'll do well over time."

Especially if the government bails out his core investments during periods of extreme drawdown, as happened during the financial crisis.

In a separate interview Buffett told Bloomberg he “overwhelmingly” supports President-elect Donald Trump’s choices for cabinet positions, many of whom are former bankers, and close friends.

“I feel that way no matter who is president,” Buffett said Thursday in New York at the premiere of a documentary about his life. “The CEO -- which I am -- should have the ability to pick people that help you run a place.”

“If they fail, then it’s your fault and you got to get somebody new,” Buffett said. “Maybe you change cabinet members or something.”

Not surprisingly, since the election, Buffett has struck a more conciliatory tone toward Trump and "called for unity." In an interview with CNN in November, he said that people could disagree with the president-elect, but ultimately he “deserves everybody’s respect.”

He concluded with an ironic twist, saying he hopes Americans are kept safe during the next administration, in view of possible aggression from North Korea. And he said he’s looking for “the people that haven’t participated in our incredible prosperity” to have a chance to do better. “If they work 40 hours a week, they should have a decent life,” Buffett said. “That’s the most important thing in terms of the economy.”

Perhaps the suggestion is that the surge in part-time jobs under Obama, as even former top white house economist Alan Krueger recently admitted, coupled with a record number of Americans holding multiple jobs, does not translate into the economic prosperity that Obama has repeatedly described as his crowning legacy.