Bloomberg led in the poll with moderates and voters over 45, was second with women and third among black voters.

The former New York mayor's strong showing qualified him for this week's Democratic debate in Las Vegas. It will be his first appearance on a presidential debate stage. Bloomberg was a late entry into the presidential campaign and has eschewed the first four nominating states, pouring money instead into national ad campaigns and stumping in Super Tuesday states.

That Bloomberg, a billionaire, is self-funding his campaign has sparked criticism that he is attempting to overwhelm the field with money and buy his way to the Democratic nomination without facing the scrutiny of the first four nominating states. Multiple candidates have expressed excitement at the prospect of debating Bloomberg, whose record as New York mayor, especially on racial issues, has been the subject of increasing criticism.

Biden, the race's onetime frontrunner, placed third in Tuesday's poll at 15 percent, down 9 points since December. Massachusetts Sen. Elizabeth Warren, also down since the last poll, ranked fourth among Democratic voters’ preferences at 12 percent, followed by Amy Klobuchar at 9 percent, up 5 points since December.

Former South Bend, Ind., Mayor Pete Buttigieg, who performed neck-and-neck with Sanders in both Iowa and New Hampshire, was at 8 percent, down from 13 percent in December.

Despite Biden’s 9-point dip among voters’ preferences, the poll shows the former vice president as the Democrat who polls the strongest against President Donald Trump. Respondents preferred him head-to-head against the president by 6 points, 50 percent to 44 percent.

Respondents preferred Bloomberg to Trump in a matchup 48 percent to 44 percent and Sanders to Trump 48 percent to 45 percent.

Sanders and Bloomberg have already upped their attacks against each other, with Sanders tweeted on Monday night: “Mr. Bloomberg, like anybody else, has the right to run for president. He does not have a right to buy the presidency.”

Bloomberg fired back with a digital video aimed at the online behavior of Sanders supporters, who have been accused of harassing those who opposed their preferred candidate. The former New York mayor stressed in his ad that the Democratic candidates need to unite the party to beat Trump.

The poll of 527 nationwide Democrats and Democratic-leaning independents was conducted Feb. 13-16 by the Marist Poll at the Marist Institute for Public Opinion via telephone and has a margin of error of 5.4 percentage points.