Democratic presidential candidate Michael Bloomberg speaks at the Greenwood Cultural Center in Tulsa, Okla., Jan. 19.
FILE - President Donald Trump speaks to reporters about border security in the briefing room of the White House, Jan. 3, 2019, in Washington.

WASHINGTON - Former New York Mayor Mike Bloomberg is an emerging presence in the fight for the U.S. Democratic presidential nomination and now Republican President Donald Trump is taking notice with his characteristic onslaught of taunts.

Democratic presidential candidate and former New York City Mayor Michael Bloomberg, right, talks with supporters during a campaign stop in Sacramento, Calif., Feb. 3, 2020.

Bloomberg's name was not on the ballot in the first two Democratic nominating contests in Iowa and New Hampshire and won't be on the next two in Nevada and South Carolina either. But he has spent more than $300 million of his own money on television ads and hiring of workers in the 14 states that vote on Super Tuesday, March 3, and others beyond then, hoping to capture the hearts of Democratic voters looking for a credible challenger to oppose Trump in November's national election.

On Thursday, Trump weighed in with his assessment, ridiculing Bloomberg's physical stature and contending his political skills are eclipsed by one of Trump's vanquished 2016 Republican foes, former Florida Gov. Jeb Bush.

"Mini Mike Bloomberg is a LOSER who has money but can’t debate and has zero presence, you will see," Trump said on Twitter. "He reminds me of a tiny version of Jeb 'Low Energy' Bush, but Jeb has more political skill and has treated the Black community much better than Mini!"

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

"Crazy Bernie" in Trumpspeak is Vermont Sen. Bernie Sanders, a self-declared democratic socialist who won the most votes in the Iowa and New Hampshire contests. But Sanders faces stiff competition from other Democratic challengers and the opposition of moderate voters who view him and his progressive policies as too liberal to defeat Trump.

Bloomberg, who actually is 5 feet, 8 inches tall (1.7 meters), responded to Trump with his own broadside.

"We know many of the same people in NY," Bloomberg said. "Behind your back they laugh at you & call you a carnival barking clown. They know you inherited a fortune & squandered it with stupid deals and incompetence."

"I have the record & the resources to defeat you," Bloomberg said. "And I will."

Trump told White House reporters Wednesday, "Frankly, I’d rather run against Bloomberg than Bernie Sanders, because Sanders has real followers, whether you like him or not, whether you agree with him or not. I happen to think it’s terrible what he says, but he has followers.”

Democratic presidential candidate former South Bend, Ind. Mayor Pete Buttigieg speaks at a campaign event, Feb. 10, 2020, in Exeter, N.H.

Former South Bend, Indiana, Mayor Pete Buttigieg, a more moderate Democrat, has edged close to Sanders in the voting in the first two states, while Minnesota Sen. Amy Klobuchar, another moderate, surged to third in New Hampshire.

From left, Democratic presidential candidates Pete Buttigieg, Sen. Bernie Sanders, Joe Biden, Elizabeth Warren, and Amy Klobuchar, are seen ahead of their primary debate at Saint Anselm College in Manchester, New Hampshire, Feb. 7, 2020.

Two other candidates, Massachusetts Sen. Elizabeth Warren and former Vice President Joe Biden, are hoping to rebound from weak performances in Iowa and New Hampshire with stronger showings as the long campaign moves to contests in Nevada and then South Carolina on the last two Saturdays of February.

Sanders, Klobuchar and others are accusing Bloomberg of using his wealth to buy the Democratic presidential nomination.

"Look, Bloomberg, anybody else in America has the right to run for president," Sanders said this week. "But I think, in a democracy, you do not have the right to buy the presidency."

He added, "It really is absurd that we have a guy who is prepared to spend already many hundreds of millions of dollars on TV ads. Meanwhile, he did not do what all of the other Democratic candidates do. He wasn’t holding town meetings in Iowa, or New Hampshire, or Nevada, or South Carolina. Those were not important enough for him."

Klobuchar tweeted recently, "I don’t think people look at the guy in the White House and say, 'Can we get someone richer?' They want someone who understands them."