Sanders hits highest support since August

Sen. Bernie SandersBernie SandersNYT editorial board endorses Warren, Klobuchar for Democratic nomination for president Trump rails against impeachment in speech to Texas farmers Biden breaks away from 2020 pack in South Carolina MORE’s (I-Vt.) support has climbed to its highest level in nearly five months, according to a new Hill-HarrisX poll of the Democratic presidential primary race.

The nationwide survey released Tuesday showed that 19 percent of respondents support Sanders, which makes him just one point shy of his previous high of 20 percent in the August 16 poll.

Former Vice President Joe BidenJoe BidenNYT editorial board endorses Warren, Klobuchar for Democratic nomination for president Trump rails against impeachment in speech to Texas farmers Biden breaks away from 2020 pack in South Carolina MORE, meanwhile, maintained the top spot with 29 percent support. Sen. Elizabeth WarrenElizabeth Ann WarrenNYT editorial board endorses Warren, Klobuchar for Democratic nomination for president Trump rails against impeachment in speech to Texas farmers Biden breaks away from 2020 pack in South Carolina MORE (D-Mass.) placed third, holding at 11 percent.

After rising to third place alongside Warren in the Jan. 3 survey, former New York City Mayor Michael BloombergMichael Rubens BloombergTrump slams Bloomberg over comments on man who shot Texas gunman Bloomberg: 'My story might have turned out very differently if I had been black' Sanders, Warren battle for progressive endorsements MORE slipped 4 percentage points to 7 percent.

Former South Bend, Ind. Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegBiden breaks away from 2020 pack in South Carolina Sanders says gender 'still an obstacle' for female politicians Sanders v. Warren is just for insiders MORE also saw a slight dip, dropping from 6 percent to 4 percent.

Sen. Amy KlobucharAmy Jean KlobucharNYT editorial board endorses Warren, Klobuchar for Democratic nomination for president Sanders v. Warren is just for insiders Buttigieg to attend MLK Day event in South Carolina after facing criticism MORE (D-Minn.) and billionaire Tom SteyerTom Fahr SteyerBiden breaks away from 2020 pack in South Carolina Buttigieg to attend MLK Day event in South Carolina after facing criticism Poll: Sanders holds 5-point lead over Buttigieg in New Hampshire MORE each received three percent support. The rest of the candidates in the crowded Democratic field polled at 2 percent or less.

The survey is likely welcome news for the Sanders campaign ahead of the Iowa caucuses.

Sanders’s campaign has intensified attacks against top rivals ahead in recent months, specifically targeting Biden and Warren.

Sanders and his aides have repeatedly gone after Biden for his past positions on racial issues and his vote in favor of the Iraq War.

Jeff Weaver, a senior adviser to the Sanders campaign, issued a statement over the weekend, saying he found it “appalling” that the former vice president “still refuses to admit he was dead wrong on the Iraq War.”

Former Secretary of State John KerryJohn Forbes KerryThe Memo: Sanders-Warren battle could reshape Democratic primary Bring on the brokered convention 18 progressive groups sign unity pledge amid Sanders-Warren feud MORE later accused Sanders of "distorting" Biden's record on Iraq.

Sanders’s campaign has also engaged in a dust-up with the Massachusetts senator's campaign, reportedly telling prospective voters that the candidate is a weak election choice because she only appeals to white educated liberals.

The back-and-forth eventually culminated with Warren’s claim that Sanders had told her during a 2018 meeting that a woman could not win a general election race against President TrumpDonald John TrumpTrump rails against impeachment in speech to Texas farmers Trump administration planning to crack down on 'birth tourism': report George Conway on Trump adding Dershowitz, Starr to legal team: 'Hard to see how either could help' MORE.

Both feuds could come to a head in Tuesday night’s Democratic primary debate. 

Sanders is among the six candidates set to take the stage in Iowa. The event marks the last debate before the Hawkeye State holds its caucus on Feb. 3.

The Hill-HarrisX survey was conducted among 451 Democratic voters and Democratic-leaning independents. It has a margin of error of plus or minus 4.5 percentage points.

—Tess Bonn