Joe Biden continues to dominate the crowded field of 2020 Democratic presidential candidates, a new Hill-Harris X poll published Wednesday shows.

According to the May 17-18 survey, the former vice president boasts support from 33 percent of registered voters who identify as Democrats or left-leaning independents.

Meanwhile, Sen. Bernie Sanders (I-Vermont) is the runner-up with 14 percent support. Sen. Elizabeth Warren (D-Massachusetts) came in third with 8 percent backing, while South Bend, Indiana Mayor Pete Buttigieg and Sen. Kamala Harris (D-California) each earned 6 percent support. Former Rep. Beto O’Rourke (D-Texas) got 5 percent backing.

None of the other 18 Democratic presidential contenders earned more than 1 percent support. Among the candidates who did not receive any backing were former Colorado Gov. John Hickenlooper, Montana Gov. Steve Bullock, Washington Gov. Jay Inslee and Rep. Eric Swalwell (D-California).

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The poll also found 19 percent of respondents were undecided.

Warren and Buttigieg are two candidates who have seen rising support in recent days. However, Biden remains the heavy frontrunner, with particularly large support among women. In total, 39 percent of female voters said the former vice president is their top choice, while 25 percent of male participants said the same thing.

Biden trails Sanders significantly in support from young voters, however, (13% vs. 24%) as a majority of Democratic-leaning Americans between the ages of 18 and 34 said they back the progressive Vermont Senator. Warren has 11 percent support in this age group.

Meanwhile, 47 percent of voters age 65 or older said Biden was their top choice.

Biden also boasted the most support among survey participants whose annual household income equals or exceeds $75,000.

The Hill-HarrisX poll was conducted among 1,030 registered voters and a margin of error of 3.1 percentage points.