Trump is said to have been fixated in recent weeks on Bloomberg, a fellow Empire State billionaire, and his stated commitment to sink a portion of his personal wealth into his own campaign and the larger effort to defeat the president's reelection effort.

For days, Trump has been hammering Bloomberg on Twitter, and he continued with the low blows on Thursday morning.

"Mini Mike is a 5'4" mass of dead energy who does not want to be on the debate stage with these professional politicians," the president tweeted. "No boxes please. He hates Crazy Bernie and will, with enough money, possibly stop him. Bernie's people will go nuts!"

Bloomberg fired back within 20 minutes, needling Trump over their shared New York contacts and ridiculing his business acumen.

".@realDonaldTrump - we know many of the same people in NY. Behind your back they laugh at you & call you a carnival barking clown," Bloomberg tweeted. "They know you inherited a fortune & squandered it with stupid deals and incompetence. I have the record & the resources to defeat you. And I will."

Trump's earlier social media post referencing Bloomberg's relationship with African American constituents comes as the Bloomberg campaign continues to face fallout from a years-old audio clip that surfaced Monday night.

The recording appears to capture an excerpt of Bloomberg's speech at an Aspen Institute event in February 2015, and he can seemingly be heard discussing the stop-and-frisk law enforcement practice he presided over as mayor of New York.

The starkly racial nature of the remarks and apparent defense of the heavily criticized policy have landed Bloomberg in hot water as he readies for Super Tuesday. His campaign has focused on amassing delegates in the more than a dozen primaries taking place on that date in early March, bypassing the four early nominating contests.

Bloomberg is likely to face further scrutiny over the clip and his mayoral record should he decide to participate in the primary debate next week in Las Vegas, an appearance Trump has argued Bloomberg is not eager to make.