Mark Cuban said Donald Trump lacks character. Allen Berezovsky via Getty Images; Bill Pugliano via Getty ImagesMark Cuban continued his criticism of former President Donald Trump in a recent interview.The billionaire said Trump is "the most unethical" person he had ever done business with.Cuban has endorsed Kamala Harris and is increasingly vocal about his dislike for Trump.Mark Cuban has a take on why former President Donald Trump has some big backers out in Silicon Valley — and it has a lot to do with Trump's character, he said.The billionaire investor and "Shark Tank" star discussed Trump's politics in an interview with YouTuber Brian Tyler Cohen earlier this week, telling the progressive commentator that Trump is "the antithesis" of someone with good character."I think they believe they can manipulate him.