Sen. Elizabeth Warren’s (D-MA) status as Joe Biden’s (D) biggest threat was solidified in an Economist/YouGov poll released ahead of the first Democrat debate Wednesday, showing Warren just six points behind Biden and four above Sen. Bernie Sanders (I-VT).

“If the Democratic presidential primary or caucus in your state were held today, who would you vote for?” the poll, conducted June 22–25, asked 1,500 U.S. adults (1,111 registered voters).

Past Economist/YouGov poll results have shown a shift, particularly among Biden, Warren, and Sanders. Sanders has been the solid second place candidate but has been losing his firm footing to Warren in recent weeks. Last week’s Economist/YouGov poll showed Warren up by 4 points over Sanders. The latest results also show Warren up by 4 points – 19 percent to Sanders’ 15 percent. Last week’s results showed Warren with 16 percent to Sanders’ 12. Biden’s lead also shrunk by one percentage point, dropping from 26 percent support to 25 percent. The number of registered voters who said they were “not sure” who they would vote for dropped by 3 points – 14 percent to 11 percent.

A large margin separates the top tier of Democrat candidates from the second tier, the poll revealed. Sen. Kamala Harris (D-CA) comes in with 7 percent support, followed by Pete Buttigieg (D) with 6 percent, and Rep. Tulsi Gabbard (D-HI) and Beto O’Rourke (D) tied at 3 percent.

2020 National Democratic Primary:

Biden 25%

Warren 19%

Sanders 15%

Harris 7%

Buttigieg 6%

Gabbard 3%

O'Rourke 3%

Bennet 1%

Booker 1%

Bullock 1%

Castro 1%

de Blasio 1%

Gillibrand 1%

Moulton 1%

Yang 1%@YouGovUS/@TheEconomist, RV, 6/22-25https://t.co/FX4npxd0DK — Political Polls (@Politics_Polls) June 26, 2019

The margin of error for the survey is +/- 2.6 percentage points when adjusted for weighting and +/-3 percent for registered voters.

Recent polls continue to spell trouble for Biden, who has been dealing with the fallout from a series of gaffes –from flip-flopping on the Hyde Amendment to praising late-segregationalist Democrat colleagues. The former was an ill-timed attempt to appeal to the extreme left, which has been protesting pro-life bills embraced by multiple states across the country. The latter was Biden’s attempt at showboating his purported ability to foster a healthy bipartisan environment. The attempt fell flat, as the segregationalist lawmakers he referred to were members of his own party.

A recent poll from Crooked Media/Change Research shows Biden slipping to second place in New Hampshire, trailing Sanders by 4 points – 24 percent to Sanders’ 28 percent. Once again, Warren found herself right on Biden’s heels with 21 percent support.