Donald Trump, Mark Cuban Feud on Twitter

President Donald Trump and Dallas Mavericks owner Mark Cuban engaged in a heated Twitter exchange Sunday morning, though exactly what prompted it is a bit of a mystery.

"I know Mark Cuban well," Trump tweeted. "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!"

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!

-- Donald J. Trump (@realDonaldTrump) February 12, 2017

Cuban first tweeted back "Lol" quoting Trump's tweet, then followed up with a screenshot of advice he gave Trump during the campaign and a dig at the president's tweeting habits.

Lol https://t.co/c4VkkX3ODP

-- Mark Cuban (@mcuban) February 12, 2017

How soon they forget .... pic.twitter.com/VXcfnjj4qX

-- Mark Cuban (@mcuban) February 12, 2017

I don't know. But isn't it better for all of us that he is tweeting rather than trying to govern ? https://t.co/953MuEdfeu

-- Mark Cuban (@mcuban) February 12, 2017

It's unclear exactly why the president chose now to blast back at Cuban, a Hillary Clinton supporter, though news outlets have pointed to possibilities.

Cuban emailed The Washington Post Sunday morning and alleged he was informed that a New York Post story inspired Trump's tweet. The story said that Cuban might be a potential foe for Trump come the 2020 presidential race, and that he's particularly threatening due to his potential Republican and independent draw.

But Trump could also be responding to comments Cuban made about American CEOs, saying that they are in " a tough situation."

"You want to make nice with the president because you're a public company and you have shareholders, and it's hard to balance doing the right financial thing versus doing what they think is the right thing, whatever your political beliefs are," Cuban added . "It's not an easy position to be in."

Many CEOs have taken issue with Trump, speaking out against his recent executive order blocking immigrants from seven Muslim-majority countries. The 9th U.S. Circuit Court of Appeals upheld a stay on the ban last week.

That's not to say all CEOs are upset with the president. Under Armour (ticker: UA, UAA) CEO Kevin Plank called Trump a U.S. "asset" on CNBC last week, which prompted Golden State Warriors player and Under Armour endorser Steph Curry to tell the San Jose Mercury News, "I agree with the description, if you remove the 'et' from asset." Cuban told the Star-Telegram he was "proud of Steph for standing up for what he believes in."

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David Oliver is Associate Editor, Social Media at U.S. News & World Report. Follow him on Twitter, connect with him on LinkedIn, or send him an email at doliver@usnews.com.