Biden, Sanders, Warren support dips in new poll

Top-tier candidates, including former Vice President Joe BidenJoe BidenBiden, Sanders lead Democratic field: poll Schumer asks McConnell for Mulvaney, Bolton to testify in impeachment trial Nadler: Giuliani trip to Ukraine shows 'crime in progress' is being committed against American democracy MORE and Sen. Bernie SandersBernie SandersBiden, Sanders lead Democratic field: poll The Memo: 2020 Democratic tensions burst to surface Sanders should fix the child food programs we already have before creating new dysfunction MORE, saw a dip in support over the past two weeks while several lower-tier candidates saw a slight uptick in their numbers, according to the latest Hill-HarrisX poll released on Wednesday.

The survey showed that 31 percent of likely Democratic primary voters back Biden, marking a 3 point drop from an identical poll conducted two weeks ago.

It also found a drop in support for Sanders and Sen. Elizabeth WarrenElizabeth Ann WarrenBiden, Sanders lead Democratic field: poll Advocates call for ObamaCare open enrollment extension after website glitches The Memo: 2020 Democratic tensions burst to surface MORE (D-Mass.), the only other two candidates in double figures in the poll.

Sanders’s support dipped 4 points to 16 percent, while Warren’s support dropped 2 points to 10 percent.

Sen. Kamala HarrisKamala Devi HarrisBooker leads other 2020 Dems in petition urging DNC to change debate qualifications Sanders revokes congressional endorsement for Young Turks founder Cenk Uygur The Hill's Campaign Report: 2020 Democrats trading jabs ahead of Los Angeles debate MORE (D-Calif.) retained her spot in fourth place but her 7 percent support is a decrease of 2 points since the July 29 poll. South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegBiden, Sanders lead Democratic field: poll Hallmark Channel reverses decision to pull ads featuring same-sex couple Advocates call for ObamaCare open enrollment extension after website glitches MORE rounded out the top five with 4 percent, a 1 point dip over the past two weeks.

Former Texas congressman Beto O’Rourke, meanwhile, held onto to sixth place with 4 percent support, which is unchanged from two weeks ago.

The number of undecided voters ticked back up to 10 percent, after briefly dropping to 8 percent.

A handful of lower-tier candidates received a slight boost. 

Gov. Steve BullockSteve BullockKamala Harris dropped out, but let's keep her mental health plan alive The Hill's Campaign Report: Democrats worry about diversity on next debate stage The Hill's Morning Report — Pelosi makes it official: Trump will be impeached MORE (D-Mont.), former San Antonio Mayor Julián Castro (D), and Sen. Amy KlobucharAmy Jean KlobucharBooker leads other 2020 Dems in petition urging DNC to change debate qualifications Democrats threaten to skip next debate over labor dispute Senate gears up for battle over witnesses in impeachment trial MORE (D-Minn.) all ticked up one point to two percent. Best-selling author Marianne WilliamsonMarianne WilliamsonThe Hill's 12:30 Report — Presented by UANI — GOP, Democrats square off at final impeachment hearing Marianne Williamson roasted for claim Trump pardoned Charles Manson Democrats take in lobbying industry cash despite pledges MORE, who had a breakout moment during the second round of Democratic debates, saw a two-point jump to 2 percent. 

The latest poll comes as a number of 2020 White House contenders make the rounds in Iowa to make their case to caucus goers.

Though the Iowa caucuses are still six months away, virtually every candidate has made an appearance at the Iowa State Fair, which is considered an essential campaign stop for presidential hopefuls on both sides of the aisle.

Many of the candidates are also scrambling to qualify for the next round of Democratic primary debates in September.

The Hill-HarrisX poll was conducted among 451 Democratic and Democratic-leaning independent voters with a margin of error of plus or minus 4.6 percentage points.

—Tess Bonn