On Sunday, President Trump posted a tweet slamming billionaire Mark Cuban.

President Trump slammed billionaire Mark Cuban on Sunday, in a tweet, noting, "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!"
Cuban has been critical of Trump lately.
In an interview with the Star-Telegram on Friday, Cuban discussed how being a CEO of a public company under the current administration can be tricky.
However, Cuban said, “Do what you think is right...Be an American citizen first."
He added, “In the bigger scheme of things, our country benefits from peaceful activism a lot more than it benefits from one more shoe being sold, or one more basketball ticket being sold, for that matter. The people that say stay away from politics are the people that are looking for politics.’’
In late January, Cuban criticized Trump’s ability to express and execute his ideas amid growing protests over his controversial immigration order.  
In a phone interview on CNBC’s 'Squawk Box', Cuban said, “To me, this is more of a question of his management style and approach to problem solving. And we’re starting to see it...You look at the wall...you look at the immigration ban--everything seems rushed.”
He later added, in part, “The question is, what is his approach...what is his management style...Just tweeting is not communicating.”