Mark Cuban may be taking on Donald Trump in the 2020 election! The billionaire said he would run as a Republican if he decides to seek presidency come 2020. “I wouldn’t run unless I have solutions. If I have solutions, then I have something to offer. If I don’t, you won’t see me anywhere near being a politician." Mark Cuban told Fox News While Cuban backed Hillary Clinton in 2016 he noted he is also "very fiscally conservative."