Biden, Sanders, Warren support dips in new poll

Top-tier candidates, including former Vice President Joe BidenJoe BidenBiden campaign cancels fundraiser with Mueller prosecutor Twitter joins Democrats to boost mail-in voting — here's why The Hill's Morning Report - Presented by Facebook - George Floyd's death sparks protests, National Guard activation MORE and Sen. Bernie SandersBernie SandersGloves come off as Democrats fight for House seat in California Senate Democrats pump brakes on new stimulus checks The Hill's Coronavirus Report: Unemployment claims now at 41 million with 2.1 million more added to rolls; Topeka mayor says cities don't have enough tests for minorities and homeless communities 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 WarrenCOVID-19 workplace complaints surge; unions rip administration Gloves come off as Democrats fight for House seat in California Police killing in Minneapolis puts new scrutiny on Biden pick 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 HarrisMinneapolis erupts for third night, as protests spread, Trump vows retaliation The Hill's Morning Report - Presented by Facebook - George Floyd's death sparks protests, National Guard activation Police killing in Minneapolis puts new scrutiny on Biden pick 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 ButtigiegPete ButtigiegBiden hopes to pick VP by Aug. 1 It's as if a Trump operative infiltrated the Democratic primary process Here's how Biden can win over the minority vote and the Rust Belt 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 BullockThe 10 Senate seats most likely to flip OVERNIGHT ENERGY: Coal company sues EPA over power plant pollution regulation | Automakers fight effort to freeze fuel efficiency standards | EPA watchdog may probe agency's response to California water issues Bullock outraises Daines in Montana Senate race MORE (D-Mont.), former San Antonio Mayor Julián Castro (D), and Sen. Amy KlobucharAmy KlobucharPolice killing in Minneapolis puts new scrutiny on Biden pick Cortez Masto says she's not interested in being Biden VP Voting rights, public health officials roll out guidelines to protect voters from COVID-19 MORE (D-Minn.) all ticked up one point to two percent. Best-selling author Marianne WilliamsonMarianne WilliamsonMarianne Williamson touts endorsements for progressive congressional candidates The Hill's 12:30 Report: Warren becomes latest 2020 rival to back Biden The Hill's Campaign Report: Biden looks to stretch lead in Tuesday contests 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