Former Vice President Joe BidenJoe BidenThe Democratic nominee won't be democratically chosen Fox's Ingraham mocks DNC over Nevada voting malfunctions: 'Are we a Third World country?' At Democratic debate, missed opportunities on immigration 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 SandersRussian interference reports rock Capitol Hill The Democratic nominee won't be democratically chosen Fox's Ingraham mocks DNC over Nevada voting malfunctions: 'Are we a Third World country?' MORE (I-Vt.), at 13 percent.

Sen. Elizabeth WarrenElizabeth Ann WarrenThe Democratic nominee won't be democratically chosen Surging Sanders looks for decisive win in Nevada Bloomberg to do interview with Al Sharpton MORE (D-Mass.) came in third with 7 percent, followed by former Rep. Beto O'RourkeBeto O'RourkeCNN signs Andrew Yang as contributor Krystal Ball: Voters are coming to their own judgements about who is electable Warren campaign to host series of events in Texas MORE (D-Texas) at 6 percent, Sen. Kamala HarrisKamala Devi HarrisHouse to vote on legislation to make lynching a federal hate crime Overnight Energy: EPA to regulate 'forever chemicals' in drinking water | Trump budget calls for slashing funds for climate science centers | House Dems urge banks not to fund drilling in Arctic refuge Democratic senators criticize plan that could expand Arctic oil and gas development MORE (D-Calif.) at 5 percent and South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegThe Democratic nominee won't be democratically chosen At Democratic debate, missed opportunities on immigration Surging Sanders looks for decisive win in Nevada MORE at 4 percent.

New Jersey Democratic Sen. Cory BookerCory Anthony BookerThe Hill's 12:30 Report: Dem anxiety grows ahead of Super Tuesday House to vote on legislation to make lynching a federal hate crime Overnight Energy: EPA to regulate 'forever chemicals' in drinking water | Trump budget calls for slashing funds for climate science centers | House Dems urge banks not to fund drilling in Arctic refuge 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 BlasioNew York attorney general threatens to sue NYC over alleged taxi fraud Bloomberg compared civil libertarians, teachers union to NRA 'extremists' in 2013: report De Blasio endorses Sanders for president MORE (D), former Colorado Gov. John HickenlooperJohn HickenlooperThe Hill's Campaign Report: What to watch for in Nevada Trump seeks to boost vulnerable GOP senator with Colorado rally Nonpartisan election forecaster moves Colorado Senate race to 'leans Democratic' MORE (D), Washington Gov. Jay InsleeJay Robert InsleeAndrew Yang ends presidential bid Bloomberg, Steyer focus on climate change in effort to stand out Our government and public institutions must protect us against the unvaccinated 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