House Democrats who know a thing or two about winning in the most competitive parts of the country are sounding the alarm about Sen. Bernie Sanders Bernie SandersMcConnell accuses Democrats of sowing division by 'downplaying progress' on election security The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters Why Democrats must confront extreme left wing incitement to violence MORE (I-Vt.) potentially becoming the party’s presidential nominee.

Vulnerable House Democrats are not only pessimistic about the Vermont senator’s chances against President Trump Donald John TrumpHR McMaster says president's policy to withdraw troops from Afghanistan is 'unwise' Cast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response MORE, they worry he could also cost Democrats the House majority in November.

Freshman Rep. Anthony Brindisi (D-N.Y.), co-chair of the centrist Blue Dogs, said he won’t back Sanders or Sen. Elizabeth Warren Elizabeth WarrenWarren, Schumer introduce plan for next president to cancel ,000 in student debt The Hill's 12:30 Report - Presented by Facebook - Don't expect a government check anytime soon No new taxes for the ultra rich — fix bad tax policy instead MORE (D-Mass.) for president, telling The Post-Standard editorial board in Syracuse that their policies “don’t necessarily align with my beliefs” and it would be “exceedingly difficult” for either candidate to win on Election Day.

ADVERTISEMENT

Another centrist, freshman Rep. Dean Phillips Dean PhillipsShakespeare Theatre Company goes virtual for 'Will on the Hill...or Won't They?' US Chamber of Commerce set to endorse 23 House freshman Democrats Minnesota Rep. Dean Phillips wins primary MORE (D-Minn.), said he has significant doubts that Sanders or Warren could beat Trump in swing states like Wisconsin and Michigan that will play a decisive role in the 2020 election.

And Rep. Scott Peters Scott H. PetersModerate Democrats push leadership to pull marijuana legislation One doctor's thoughts on a hopeful future Pelosi axes idea of Saturday vote on additional COVID relief MORE (D-Calif.) warned that having Sanders at the top of the ticket would be an electoral disaster that could put the “House majority at risk.”

The dire warnings from moderate Democrats have become more urgent and aggressive as Sanders fought to a virtual tie with former South Bend, Ind., Mayor Pete Buttigieg Pete ButtigiegBogeymen of the far left deserve a place in any Biden administration Overnight Defense: Woodward book causes new firestorm | Book says Trump lashed out at generals, told Woodward about secret weapons system | US withdrawing thousands of troops from Iraq A socially and environmentally just way to fight climate change MORE in Iowa and appeared poised to win the New Hampshire primary on Tuesday.

Democrats are particularly uneasy about a party standard-bearer who labels himself a “democratic socialist,” as Sanders does.

“Sanders is about the worst candidate we can put up. He not only won’t likely win the presidency; he puts the House majority at risk,” Peters, who has endorsed former New York City Mayor Michael Bloomberg Michael BloombergTop Democratic super PAC launches Florida ad blitz after Bloomberg donation The Hill's 12:30 Report - Presented by Facebook - Latest with the COVID-19 relief bill negotiations The Memo: 2020 is all about winning Florida MORE (D) and represents a district that’s become bluer in recent years.

“I will support Bernie Sanders if he is nominated against Donald Trump; I will do so enthusiastically,” Peters told The Hill on Tuesday, while adding “I don’t think … putting a socialist on the ballot is a good strategy to defeat Donald Trump.”

ADVERTISEMENT

Freshman Rep. Max Rose Max RoseThe Hill's Morning Report - Sponsored by The Air Line Pilots Association - Pence lauds Harris as 'experienced debater'; Trump, Biden diverge over debate prep Navy cancels training flight over NYC on 9/11 after criticism FDNY says Treasury withheld .7M from 9/11 first responder fund MORE (D-N.Y.), whose Staten Island district went for Trump by about 10 points in 2016, also sought to distance himself from any socialist label.

“I’m not a socialist. I’m thinking about printing T-shirts saying as much. I think socialist economic policies fail, inevitably,” said Rose, another Bloomberg backer.

Asked how Sanders would likely play in his district, Rose predicted “probably not very well.”

Rep. Henry Cuellar (D-Texas), who faces a primary challenge from the left this cycle, also expressed trepidation about the prospect of having Sanders as the standard-bearer.

“I'm a Democrat," Cuellar said Tuesday. "I think it would be difficult to have a socialist at the top of the ticket. I think he clarifies it and says 'a democratic socialist,' but a socialist is a socialist, whether it's Republican socialist or democratic socialist, if there is such a thing."

Most frontline Democrats have not endorsed anyone for president. But former Vice President Joe Biden Joe BidenCast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response Biden tells CNN town hall that he has benefited from white privilege MORE leads with nine endorsements from Democrats representing competitive districts, while Bloomberg is quickly catching up, notching five as of Tuesday.

One GOP target, freshman Rep. Katie Porter (D-Calif.), has backed Warren. Sanders, however, has yet to secure an endorsement from a Democratic lawmaker in a swing district.

Another frontline freshman, Phillips of Minnesota, is backing his home-state senator, Sen. Amy Klobuchar Amy KlobucharEPA delivers win for ethanol industry angered by waivers to refiners It's time for newspapers to stop endorsing presidential candidates Biden marks anniversary of the Violence Against Women Act, knocks Trump and McConnell MORE (D-Minn.). Asked if a Sanders nomination would give him heartburn, Phillips joked: “You mean heart-Bernie?”

“I’m not going to disparage, I’m not going to prognosticate. But yes, I’m concerned about someone who, in the six states that really matter in this election, could change the outcome of an election that we should win,” Phillips told The Hill. “It causes concern if it is not a candidate who can generate the independent and even moderate Republican support we’re going to need to replace Donald Trump."

And Phillips agreed with Peters's prediction that a Sanders nomination would create a detrimental “down-ballot effect” for congressional Democrats.

One vulnerable Democrat put it this way: “There is a fear in the caucus that if it’s not a ‘B’ or a ‘K’ at the top of the ticket — Biden, Buttigieg, Bloomberg or Klobuchar — we’re in real trouble.”

Sanders’s top surrogates on Capitol Hill argued it’s shortsighted for Democrats like Brindisi to declare they won’t back the Vermont senator.

ADVERTISEMENT

“The stakes are way too high in this election. I’m not going to huff and puff if my candidate doesn’t secure the nomination,” freshman Rep. Alexandria Ocasio-Cortez Alexandria Ocasio-CortezWhy Democrats must confront extreme left wing incitement to violence The Hill Interview: Jerry Brown on climate disasters, COVID-19 and Biden's 'Rooseveltian moment' House Democrats postpone vote on marijuana decriminalization bill MORE (D-N.Y.), who also describes herself as a democratic socialist, told The Hill on Tuesday. “I think we need to be mature enough to recognize the threat that is coming from the White House and come together behind the eventual nominee, no matter who that is.”

Campaigning alongside Sanders just a day earlier in New Hampshire, Ocasio-Cortez made the case for why Sanders is in the best position to beat Trump: Sanders, she argued, has tapped into a massive political movement against "hate" and "divisiveness."

“We are at a crossroads in our democracy … and that is why we need to nominate someone with a political revolution at their back, with decades of organizing bringing us to this moment,” Ocasio-Cortez told the crowd at the University of New Hampshire in Durham.

“It is not going to be any one candidate that defeats Donald Trump; it’s going to be a movement of Americans that defeat Donald Trump in a rejection of hatred and an embracing of love,” she added.

Despite their clear misgivings, many vulnerable freshman Democrats were reluctant to follow Brindisi’s lead and say they would refuse to back Sanders or Warren. Rep. Mikie Sherrill Rebecca (Mikie) Michelle SherrillHillicon Valley: DOJ indicts Chinese, Malaysian hackers accused of targeting over 100 organizations | GOP senators raise concerns over Oracle-TikTok deal | QAnon awareness jumps in new poll House passes legislation to boost election security research Lawmakers call for bipartisan push to support scientific research MORE (D-N.J.) said she will stand with the eventual nominee of her party, as will Rep. Elaine Luria Elaine Goodman LuriaUS Chamber of Commerce set to endorse 23 House freshman Democrats House panel votes against curtailing Insurrection Act powers after heated debate Republican Scott Taylor wins Virginia primary, to face Elaine Luria in rematch MORE (D-Va.).

“I am behind whoever wins the nomination,” Luria, a Biden backer, told The Hill. “I don’t like some of their policies, but, you know.”

ADVERTISEMENT

Freshman Rep. Haley Stevens Haley Maria StevensUS Chamber of Commerce set to endorse 23 House freshman Democrats Eric Esshaki wins Michigan GOP primary to challenge Haley Stevens The Hill's Campaign Report: Buzz builds around Warren for VP MORE (D-Mich.), who has endorsed Bloomberg, said she will follow the former New York City mayor’s lead if he doesn’t secure the nomination.

“Should he not get the nomination,” she said, “we will support whoever does to defeat this president.”

A reporter on Tuesday asked Rep. Cheri Bustos Cheryl (Cheri) Lea BustosThe Hill's Campaign Report: Biden asks if public can trust vaccine from Trump ahead of Election Day | Oklahoma health officials raised red flags before Trump rally DCCC dropping million on voter education program Clark rolls out endorsements in assistant Speaker race MORE (D-Ill.), the chairwoman of House Democrats’ campaign arm who represents a district that Trump won in 2016, how many of her members had approached her saying they were worried about Sanders.

Bustos paused for a full 5 seconds before answering.

“We have discussions about the nominee, but it runs the gamut,” she said.

Juliegrace Brufke contributed.