Biden maintains 19-point lead over Sanders in new poll

Former vice president Joe BidenJoe BidenThe media have fallen out of love with Bernie, but have voters? Top Zelensky aide refutes Sondland testimony The great AI debate: What candidates are (finally) saying about artificial intelligence MORE leads Sen. Bernie SandersBernie SandersSanders urges impeachment trial 'quickly' in the Senate The media have fallen out of love with Bernie, but have voters? Steyer rolls out 5B plan to invest in historically black colleges MORE in the latest Hill-HarrisX poll released Monday by 19 points, maintaining a clear separation from the rest of the field in the Democratic presidential primary,

Biden won 35 percent support from Democratic and Democratic-leaning independent registered voters in the June 1-2 survey, compared to 16 percent for Sanders (I-Vt.).

South Bend, Ind. Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegThe media have fallen out of love with Bernie, but have voters? Tulsi Gabbard reacts to Afghanistan report, calls out Pete Buttigieg's McKinsey work Buttigieg surrogate on candidate's past consulting work: 'I don't think it matters' MORE was a distant third with 8 percent. He was followed by Sen. Elizabeth WarrenElizabeth Ann WarrenThe media have fallen out of love with Bernie, but have voters? Buttigieg surrogate on candidate's past consulting work: 'I don't think it matters' Steyer rolls out 5B plan to invest in historically black colleges MORE (D-Mass) at 5 percent.

Sen. Kamala HarrisKamala Devi HarrisThe media have fallen out of love with Bernie, but have voters? Krystal Ball: Media turns on Buttigieg, will this end him? Senate Democrats demand Trump fire Stephen Miller MORE (D-Calif.) and former Rep. Beto O'RourkeBeto O'RourkeButtigieg picks up third congressional endorsement from New York lawmaker Klobuchar hires staff in Nevada Deval Patrick enters 2020 race MORE were supported by 4 percent of respondents while Sen. Cory BookerCory Anthony BookerSanders urges impeachment trial 'quickly' in the Senate Steyer rolls out 5B plan to invest in historically black colleges The great AI debate: What candidates are (finally) saying about artificial intelligence MORE (D-N.J.) was named by 3 percent.

All of the other Democratic candidates were named by 1 percent or fewer survey participants. Seventeen percent of respondents said they were unsure about their preference.

The results overall are largely similar to a May 17-18 Hill-HarrisX survey which also found Biden with a 19 percent lead over his Vermont-based rival. The former vice president received 33 percent support in the earlier poll while Sanders received 14 percent.

The May survey showed Warren in third place with 8 percent support and Buttigieg in fourth with 6 percent. The shift between the two candidates' support within the polls is within the surveys' sampling margins of error.

The newer poll found Biden as the top named candidate of both men and women and also across all age groups, although his lead over Sanders among voters between 18 and 34 was just one point, indicating a statistical tie. Older voters were overwhelmingly more likely to prefer the former vice president to other candidates with 47 percent of respondents 50 years old and older supporting him.

Among white voters, Biden was the preferred candidate while Sanders and Buttigieg were essentially tied for second-place. Biden enjoyed an even stronger lead among black respondents while Sanders showed strength among Hispanics although the sample size for both groups is too small to state this definitively.

Since Biden's entry into the presidential contest in April, the race has become relatively stable with no candidate able to dislodge Sanders from second-place and Biden from first, although that may change following the first debate contest which will be hosted by the Democratic National Committee June 26 and 27.

Presidential aspirants sharpened their messages over the weekend at the California Democratic Party's annual convention in San Francisco where several candidates called for impeaching President TrumpDonald John TrumpSanders urges impeachment trial 'quickly' in the Senate US sending 20,000 troops to Europe for largest exercises since Cold War Barr criticizes FBI, says it's possible agents acted in 'bad faith' in Trump probe MORE. Former Colorado Gov. John HickenlooperJohn HickenlooperThe Hill's 12:30 Report: Impeachment enters new crucial phase Bullock drops White House bid, won't run for Senate 2020 hopes rise for gun control groups after Virginia elections MORE was booed by attendees after he expressed skepticism about a proposed Green New Deal environmental initiative and proposals to have the federal government administer medical insurance for all Americans.

Warren and Buttigieg took veiled swipes at Biden at the event with the Massachusetts senator implicitly denouncing his recent declarations that Republicans would become more inclined toward bipartisanship if President Trump is defeated in 2020. Buttigieg said that Democrats needed "a new generation of leaders," a reference to Biden's age of 76 years.

Sanders indirectly slammed Biden for skipping the event and argued that the party would not be able to defeat Trump unless it embraced a progressive agenda.

The latest Hill-HarrisX survey was conducted June 1-2 among a statistically representative sample of 1,001 registered voters. The question about 2020 Democratic presidential preference was asked of a subset of 431 respondents who said they were Democrats or independents who leaned toward the Democratic Party.

The larger survey has a 3.1 percent sampling margin of error and a 95 percent confidence level. The subset has a sampling margin of error of 4.7 percentage points.

—Matthew Sheffield