Sanders hits highest support since August

Sen. Bernie SandersBernie SandersDrugmaker caps insulin costs at to help diabetes patients during pandemic The Hill's Campaign Report: Wisconsin votes despite coronavirus pandemic Sen. Brown endorses Biden for president 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 BidenTrump shakes up WH communications team The Hill's Campaign Report: Wisconsin votes despite coronavirus pandemic The Intercept's Ryan Grim says Cuomo is winning over critics MORE, meanwhile, maintained the top spot with 29 percent support. Sen. Elizabeth WarrenElizabeth WarrenHillicon Valley: Schiff presses intel chief on staff changes | Warren offers plan to secure elections | Twitter's Jack Dorsey to donate B to coronavirus fight | WhatsApp takes steps to counter virus misinformation Warren releases plan to secure elections during coronavirus pandemic On The Money: Trump officials struggle to get relief loans out the door | Dow soars more than 1600 points | Kudlow says officials 'looking at' offering coronavirus bonds 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 BloombergNew York City auctioned off extra ventilators due to cost of maintenance: report DNC books million in fall YouTube ads Former Bloomberg staffer seeks class-action lawsuit over layoffs MORE slipped 4 percentage points to 7 percent.

Former South Bend, Ind. Mayor Pete ButtigiegPete ButtigiegButtigieg launches new PAC to aid down-ballot candidates HuffPost political reporter on why Bernie fell way behind Biden Economists fear slow pace of testing will prolong recession MORE also saw a slight dip, dropping from 6 percent to 4 percent.

Sen. Amy KlobucharAmy Klobuchar Klobuchar's husband recounts battle with coronavirus: 'It just suddenly hit me' Hillicon Valley: Schiff presses intel chief on staff changes | Warren offers plan to secure elections | Twitter's Jack Dorsey to donate B to coronavirus fight | WhatsApp takes steps to counter virus misinformation Wisconsinites put lives on the line after SCOTUS decision MORE (D-Minn.) and billionaire Tom SteyerTom SteyerProgressive advocates propose T 'green stimulus' plan Candidates want data privacy rules, except for their own campaigns Budowsky: Biden should pull together a 'dream team of rivals' 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 KerryHistory's lessons for Donald Trump US inaction is hurting the chance for peace in Libya Poll: More Republican voters think party is more united than Democratic voters 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 TrumpCDC updates website to remove dosage guidance on drug touted by Trump Trump says he'd like economy to reopen 'with a big bang' but acknowledges it may be limited Graham backs Trump, vows no money for WHO in next funding bill 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