Former Vice President Joe BidenJoe BidenBiden compares Trump to George Wallace Sanders unveils plan to guarantee the 'right to a secure retirement' CNN Democratic debate drawing finishes third in cable news ratings race MORE leads his closest competitor in the field of Democratic presidential candidates by 22 percentage points, according to a Hill-HarrisX poll released Monday.

In the June 14-15 survey, Biden garnered support from 35 percent of registered voters who identified as Democrats or as independents who favored the party. The next closest candidate was Sen. Bernie SandersBernie SandersGabbard arrives in Puerto Rico to 'show support' amid street protests Democratic strategist predicts most 2020 candidates will drop out in late fall Sanders unveils plan to guarantee the 'right to a secure retirement' MORE (I-Vt.), at 13 percent.

Sen. Elizabeth WarrenElizabeth Ann WarrenJulián Castro is behind in the polls, but he's finding a niche Gabbard arrives in Puerto Rico to 'show support' amid street protests Democratic strategist predicts most 2020 candidates will drop out in late fall MORE (D-Mass.) came in third with 7 percent, followed by former Rep. Beto O'RourkeBeto O'RourkeThe Hill's Campaign Report: Second debate lineups set up high-profile clash Biden, Harris set for second Democratic debate showdown 2020 Democrats react to 'send her back' chants at Trump rally MORE (D-Texas) at 6 percent, Sen. Kamala HarrisKamala Devi HarrisWhat to expect when Mueller testifies: Not much Biden compares Trump to George Wallace CNN Democratic debate drawing finishes third in cable news ratings race MORE (D-Calif.) at 5 percent and South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegDemocratic strategist predicts most 2020 candidates will drop out in late fall The Hill's 12:30 Report: Trump hits media over 'send her back' coverage The Hill's Campaign Report: Second debate lineups set up high-profile clash MORE at 4 percent.

New Jersey Democratic Sen. Cory BookerCory Anthony BookerDemocratic strategist predicts most 2020 candidates will drop out in late fall The Hill's 12:30 Report: Trump hits media over 'send her back' coverage The Hill's Campaign Report: Second debate lineups set up high-profile clash MORE drew 3 percent support, while former Housing and Urban Development Secretary Julián Castro was named by 2 percent.

All other candidates who were named by poll participants received 1 percent support or less. Several were not named by any participants: New York Mayor Bill de BlasioBill de BlasioDemocratic strategist predicts most 2020 candidates will drop out in late fall The Hill's 12:30 Report: Trump hits media over 'send her back' coverage The Hill's Campaign Report: Second debate lineups set up high-profile clash MORE (D), former Colorado Gov. John HickenlooperJohn Wright HickenlooperDemocratic strategist predicts most 2020 candidates will drop out in late fall The Hill's 12:30 Report: Trump hits media over 'send her back' coverage The Hill's Campaign Report: Second debate lineups set up high-profile clash MORE (D), Washington Gov. Jay InsleeJay Robert InsleeDemocratic strategist predicts most 2020 candidates will drop out in late fall The Hill's Campaign Report: Second debate lineups set up high-profile clash Biden, Harris set for second Democratic debate showdown MORE (D) and former Sen. Mike Gravel (D-Alaska).

Biden's 35 percent matches the support rating he received in a Hill-HarrisX survey conducted June 1-2. In that poll, Sanders had 16 percent support.

Biden was slightly more popular among male respondents than among female voters in the most recent survey, with 37 percent of men favoring him compared to 32 percent of women.

For Sanders, 16 percent of men supported him, compared to support from 10 percent of women.

Harris received more support from female respondents than males, with 8 percent of women backing her compared to 2 percent of men.

Biden had support from 22 percent of Hispanic respondents, compared with 15 percent for Sanders 13 percent for O'Rourke and 10 percent for Harris. In the previous poll, Biden and Sanders were tied among Latino respondents at 25 percent.

The former vice president fared much better among African-American voters, with 42 percent support. None of the other candidates received double-digit support. In the previous three surveys, Biden was the overwhelming favorite among black respondents.

Biden has also maintained an edge among white Democratic voters, at 36 percent. Sanders was next at 12 percent, followed by 9 percent for Warren.

The June 14-15 Hill-HarrisX poll was conducted online among a statistically representative sample of 424 respondents who identified themselves as registered voters who were Democrats or independents who favored the Democratic Party. It has a sampling margin of error of 4.8 percent and a 95 percent confidence level.

—Matthew Sheffield