Article continues below advertisementLeaked emails from Jeffrey Epstein's private correspondence have revealed that he once mocked Donald Trump's mental state, suggesting the president showed signs of "early dementia."The convicted s-- trafficker, who was once friendly with Trump, appeared to have turned on him by the time the real estate mogul entered the White House in 2017. According to messages obtained by the House Oversight Committee, Epstein warned former Obama White House counsel Kathryn Ruemmler in 2018 not to underestimate Trump's power.