Sanders hits highest support since August

Sen. Bernie SandersBernie SandersSirota reacts to report of harassment, doxing by Harris supporters Republicans not immune to the malady that hobbled Democrats The Hill's Morning Report - Sponsored by Facebook - Republicans lawmakers rebuke Trump on election 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 BidenFormer Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick Bloomberg rolls out M ad buy to boost Biden in Florida MORE, meanwhile, maintained the top spot with 29 percent support. Sen. Elizabeth WarrenElizabeth WarrenOvernight Defense: Appeals court revives House lawsuit against military funding for border wall | Dems push for limits on transferring military gear to police | Lawmakers ask for IG probe into Pentagon's use of COVID-19 funds On The Money: Half of states deplete funds for Trump's 0 unemployment expansion | EU appealing ruling in Apple tax case | House Democrats include more aid for airlines in coronavirus package Warren, Khanna request IG investigation into Pentagon's use of coronavirus funds 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 BloombergBloomberg rolls out M ad buy to boost Biden in Florida Democratic groups using Bloomberg money to launch M in Spanish language ads in Florida Bloomberg pays fines for 32,000 felons in Florida so they can vote MORE slipped 4 percentage points to 7 percent.

Former South Bend, Ind. Mayor Pete ButtigiegPete ButtigiegBillionaire who donated to Trump in 2016 donates to Biden The Hill's Morning Report - Sponsored by Facebook - GOP closes ranks to fill SCOTUS vacancy by November Buttigieg stands in as Pence for Harris's debate practice MORE also saw a slight dip, dropping from 6 percent to 4 percent.

Sen. Amy KlobucharAmy Klobuchar3 reasons why Biden is misreading the politics of court packing Social media platforms put muscle into National Voter Registration Day Battle lines drawn on precedent in Supreme Court fight MORE (D-Minn.) and billionaire Tom SteyerTom SteyerTV ads favored Biden 2-1 in past month Inslee calls Biden climate plan 'perfect for the moment' OVERNIGHT ENERGY: Trump administration finalizes plan to open up Alaska wildlife refuge to drilling | California finalizes fuel efficiency deal with five automakers, undercutting Trump | Democrats use vulnerable GOP senators to get rare win on environment 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: Warning signs flash for Trump on debates Divided country, divided church TV ads favored Biden 2-1 in past month 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 TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick 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