The Sanders campaign and supporters are signaling concern after the socialist senator lost the coveted Working Families Party endorsement to Sen. Elizabeth Warren (D-MA), according to recent reports.

The Working Families Party – which backed Sen. Bernie Sanders (I-VT) in 2015 – chose to endorse Warren over the Vermont socialist, it was revealed on Monday.

“Senator Warren strikes fear into the hearts of the robber barons who rigged the system, and offers hope to millions of working people who have been shut out of our democracy and economy,” WFP’s National Party Director Maurice Mitchell said in a statement, according to Politico.

According to Politico’s report, the vast majority of WFP members chose Warren over Sanders, 61 percent to 36 percent. The news coincides with the Sanders campaign’s shakeup in New Hampshire, moving presidential campaign operations state director Joe Caiazzo to Massachusetts and filling his New Hampshire post with Shannon Jackson, who served as a senior adviser during Sanders’ 2016 presidential bid and ran his 2018 Senate reelection campaign.

The move also followed rumblings of a Warren surge among Democrat insiders, including uncommitted delegates in the Granite State – many of whom are actively considering Warren. Additionally, a CBS/YouGov Tracker released last week spelled more trouble for the Sanders campaign, showing his ideological ally narrowly edging him – and Joe Biden (D) – out as the leader in the early primary state:

2020 New Hampshire Democratic Primary:

Warren 27%

Biden 26%

Sanders 25%

Buttigieg 8%

Harris 7%

Booker 2%

Klobuchar 1%

Steyer 1%

Gabbard 1%

Yang 1%

O'Rourke 1%@YouGovUS/@CBSNewsPoll 8/28-9/4 — Political Polls (@Politics_Polls) September 8, 2019

Warren’s increasing popularity and rise in enthusiasm is causing concern among Sanders supporters.

“Seeing the campaign not be able to outshine Warren with WFP progressives doesn’t have me questioning WFP’s process,” Rafael Shimunov, a former Sanders volunteer and former national creative director for WFP told Politico.

“It has me questioning where the Bernie campaign could have done better, because I want to make sure the strongest candidate unmasks Biden and unseats Trump,” Shimunov added.

Politico reported:

“In 2016, Bernie was the David who beat Goliath in New Hampshire — the expectations this time around are incomparable,” said Andrew Feldman, a Democratic strategist with close ties to labor groups. “It would be a mistake to try to replicate the type of campaign that Sanders ran in New Hampshire in 2016 because the dynamics of this race are completely different. For Sanders to be successful, a professional operation is critical.” Jeff Weaver, a top Sanders adviser, told POLITICO that numerous rank-and-file members in the Working Families Party support Sanders and that his ground game in New Hampshire and other early states is strong. Sanders has 14 times as many identified voters in the Granite State than it had at this time in 2016, according to his campaign, and is doubling his field staff there from 26 to 50 employees. He also said the campaign’s national and states staff are in daily contact, and that he has a regular “states call” in which he asks his aides across the country to be honest about the problems they’re seeing.

However, an NBC/WSJ national poll released Tuesday signaled more trouble for the Sanders campaign, showing Biden and Warren pulling away as the clear frontrunners and leading the remaining candidates, including Sanders, by double digits.

As Breitbart News reported:

The poll, which surveyed 506 Democrat primary voters September 13 – 16, shows Biden and Warren pulling away from the rest of the pack, with Biden leading by 31 percent support. He is followed by Warren, who garnered 25 percent support. Notably, Sen. Bernie Sanders (I-VT) – a longtime top tier candidate – fell behind Warren by double-digits, seeing just 14 percent support. No other candidate saw over seven percent support, with Mayor Pete Buttigieg (D) garnering seven percent support, Sen. Kamala Harris (D-CA) seeing five percent, and Andrew Yang (D) taking in four percent. The margin of error is +/- 4.36 percent.

According to Politico, Sanders campaign staffers have been “calling members of their steering committee” over concerns with the media’s narrative on the campaign’s internal shakeups and speculation of increasing worries regarding the ground game of his close competitors:

POLITICO spoke with nearly a dozen current and former Sanders advisers and allies, some of whom declined to discuss internal dynamics on the record because of fear of retribution. Since Sunday, campaign staffers have been calling members of their steering committee, asking them not to speak to the media because stories about the internal shakeup were published, according to three people who received the calls.

A pair of primary state polls released Wednesday likely further the campaign’s existing concerns, with an Iowa poll showing both Biden and Warren leading by double digits and Mayor Pete Buttigieg (D) edging out Sanders for third place in the state. Similarly, a Florida poll also showed Sanders down by double digits, garnering 14 percent to Biden’s 34 percent and Warren’s 24 percent:

#NEW Iowa Democratic Caucus, Pot-Debate Poll Biden 25%

Warren 23%

Buttigieg 12%

Sanders 9%

Klobuchar 8%

Harris 5%

Steyer 3%

Booker 2%

Yang 2%

Bullock/Castro/Delaney/Gabbard/O’Rourke 1%@focusonrural / David Binder Researchhttps://t.co/0eu508GFxB — Political Polls (@PpollingNumbers) September 18, 2019

#Florida Democratic Primary:

Biden 34%

Warren 24%

Sanders 14%

Buttigieg 5%

Harris 4%

Messam 3%

O'Rourke 2%

Yang 2%

Gabbard 1%

de Blasio 1%

Ryan 1%

Booker 1%

Bullock 1%

Bennet 1%

Steyer 0%

Castro 0%

Klobuchar 0%

Delaney 0%

Sestak 0%

Williamson 0%@FloridaAtlantic 9/12-15 pic.twitter.com/AFBM1NzpeI — Political Polls (@Politics_Polls) September 18, 2019

The current Real Clear Politics average shows Sanders two points behind Warren– 16.1 percent to the Massachusetts senator’s 17.7 percent.