Billionaire Mark Cuban may have left the door open for a future presidential run.

Billionaire Mark Cuban may have left the door open for a future presidential run. 
Business Insider reports that when he was asked about the possibility, he wrote back, “We will see.”
The conversation was sparked by a tweet posted by President Trump on Sunday which read, “I know Mark Cuban well. He backed me big-time but I wasn't interested in taking all of his calls. He's not smart enough to run for president!”
In response, Cuban initially tweeted back, “LOL.” 
He then posted two images of previous communications with Trump--one where Cuban congratulates him on his victory and another where Cuban appears to give Trump some encouraging advice during the campaign; the accompanying message reads, “How soon they forget…” 
Less than 30 minutes later, Cuban responded to a user who asked why Trump had spoken out against him by tweeting back, “I don't know. But isn't it better for all of us that he is tweeting rather than trying to govern?” 
However, the Washington Post reports that “Cuban said he had been told that Trump was reacting to a New York Post story in which Cuban is mentioned as a possible challenger for Trump in the 2020 presidential campaign.” 
The piece is said to have compared Cuban’s appeal as a wealthy, unconventional candidate to the qualities that made Trump successful.
Cuban himself has previously expressed mixed thoughts about running; in September 2015, he told CNBC, “I just don't have the temperament, at least not at this point, to be a politician.” 
But less than a year later in May 2016, he said on NBC’s 'Meet the Press,' “Well, it's certainly more of a consideration than it was. You don't have to be the perfect Stepford candidate like you would've been in the past.”