Former Vice President Joe BidenJoe BidenButtigieg surges ahead of Iowa caucuses GOP eager for report on alleged FBI surveillance abuse Biden leads among Latino Democrats in Texas, California 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 SandersButtigieg surges ahead of Iowa caucuses Biden leads among Latino Democrats in Texas, California On The Money: Trump appeals to Supreme Court to keep tax returns from NY prosecutors | Pelosi says deal on new NAFTA 'imminent' | Mnuchin downplays shutdown threat | Trump hits Fed after Walmart boasts strong earnings MORE (I-Vt.), at 13 percent.

Sen. Elizabeth WarrenElizabeth Ann WarrenButtigieg surges ahead of Iowa caucuses Biden leads among Latino Democrats in Texas, California Following school shooting, Biden speaks out: 'We have to protect these kids' MORE (D-Mass.) came in third with 7 percent, followed by former Rep. Beto O'RourkeBeto O'RourkeDeval Patrick enters 2020 race O'Rourke says he 'absolutely' plans to stay in politics Krystal Ball: Buttigieg is 'the boomer candidate' MORE (D-Texas) at 6 percent, Sen. Kamala HarrisKamala Devi HarrisBiden leads among Latino Democrats in Texas, California Overnight Health Care: Cigarette smoking rates at new low | Spread of vaping illness slowing | Dems in Congress push to block Trump abortion rule Democratic senators introduce bill to push ICE to stop 'overuse' of solitary confinement MORE (D-Calif.) at 5 percent and South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegButtigieg surges ahead of Iowa caucuses Overnight Health Care: Cigarette smoking rates at new low | Spread of vaping illness slowing | Dems in Congress push to block Trump abortion rule Ocasio-Cortez jabs 'plutocratic' late entrants to 2020 field MORE at 4 percent.

New Jersey Democratic Sen. Cory BookerCory Anthony BookerDemocratic senators introduce bill to push ICE to stop 'overuse' of solitary confinement Krystal Ball: Patrick's 2020 bid is particularly 'troublesome' for Warren 2020 Democrats demand action on guns after Santa Clarita shooting 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 BlasioDeval Patrick enters 2020 race De Blasio slams Bloomberg run for president: He 'epitomizes the status quo' The Hill's 12:30 Report: Washington braces for public impeachment hearings MORE (D), former Colorado Gov. John HickenlooperJohn HickenlooperKrystal Ball dismisses Rahm Emanuel's 'Medicare for All' criticism as a 'corporatist mantra' Trump says remark about Colorado border wall was made 'kiddingly' Colorado governor mocks Trump for saying he's building wall there MORE (D), Washington Gov. Jay InsleeJay Robert InsleeO'Rourke ends presidential bid Sunrise Movement organizer: Sanders, Warren boast strongest climate change plans Overnight Energy: Farmers say EPA reneged on ethanol deal | EPA scrubs senators' quotes from controversial ethanol announcement | Perry unsure if he'll comply with subpoena | John Kerry criticizes lack of climate talk at debate 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