SPENCER, Iowa — Elizabeth Warren’s “Medicare for all” government-financed healthcare plan is unnerving Iowa Democrats as the prospect of her seizing the 2020 Democratic presidential nomination becomes more real.

Voters in the first nominating contest state say they're scared both about the $26 trillion price tag of "Medicare for all" and the opening it could give President Trump to tag the Massachusetts senator as a socialist whose efforts to abolish private health insurance would lead to the collapse of the American healthcare system.

It's becoming a serious challenge for the Warren campaign, which has a natural group of voters who vehemently want to oust Trump in 2020 but are leery of Warren's far-left policy proposals.

Tim Fairchild, 60, an independent voter whose No. 1 issue is healthcare, said he is “wide open” in the 2020 primaries, but Warren's plan is giving him pause. “I'm not saying it's wrong, but I'm scared. I really am. I’d be scared to have an appendectomy, too — it’s big, it’s bold, it may be great,” he told the Washington Examiner after a Pete Buttigieg town hall in Spencer.

Fairchild, owner of a welding and machine shop, said he admires Warren’s grit since he‘d written her off after Trump nicknamed her “Pocahontas,” mocking her for her Native American ancestry claim. “The only reason she's back is perseverance and tenacity. That's what it takes to make millionaires and good leaders,” But, he added, “If she's off by 2% on any of her predictions, that's like a gazillion-dollar error.”

Democrats are grappling with the politics of “Medicare for all” as they hurtle toward the Iowa caucuses, now less than 100 days away on Feb. 3. The promise of universal health coverage has become a litmus test as the party lurches to the left, yet fissures have formed over how to get there.

The legislation, championed by Vermont Sen. Bernie Sanders, caused problems for California Sen. Kamala Harris earlier in the cycle after she came out in favor of eliminating private health insurance, a provision in the bill. Despite being one of the first senators to sign onto Sanders’ measure, Harris walked back her comments and tried to counter “flip-flop” criticism by releasing her own plan and saying she'd heard voters’ concerns about keeping their healthcare providers.

Now, Warren is facing her own “Medicare for all” test. The senator’s assertion she was “with Bernie” except for his admission that middle-class taxes would go up to pay for the program drew scrutiny from voters, reporters, and her rivals. Under pressure, she made public her plan to fund “Medicare for all,” with the promise to roll out additional specifics regarding how she proposed to transition to the framework.

[Related: Elizabeth Warren: 2M lost jobs 'part of the cost' of 'Medicare for all']

Faye Schluter, 58, an undecided Democrat who works as a nonprofit organization executive, hasn’t warmed to Warren because “she has her own agendas.”

“I don't think she's talking with the society, with people, what we want,” Schluter said at another Buttigieg event, this time in Algona. “She has her agenda of control, and I think people are getting sick of it because what they're wanting — they, as in our big government system — I mean the layers of corruption I believe are so deep. How is that person going to start chipping away at that? And I think she's part of all of that.”

“Extreme” stances sometimes reflect the candidate’s actual positions or are taken up in an effort to differentiate themselves to a primary electorate comprised of more extreme voters, according to Northeastern University’s Costas Panagopoulos. Regardless, they always carry the risk of alienating centrists, he told the Washington Examiner.

Panagopoulos added that the danger for Warren is Democrats’ preoccupation with electability, even among those who share her views.

“In an election in which electability will be paramount for Democratic primary voters, adopting extreme positions is risky and potentially fatal,” he said.

For Tom Cochran, a 720 Strategies partner, another boon for Warren and “Medicare for all” is that it's boosted her media mentions, though he said he suspects the eventual nominee "will gravitate back to the center during the general election."

"The question of electability seems to be playing a bigger part this cycle, so much so that voters are prioritizing that over issues. So yes, it definitely raises concerns for the candidates of they are being evaluated subjectively on whether they can beat Trump versus are their policy positions good for the country?" Cochran said.

Jared Gerlock, 40, an Iowa Democrat who's leaning toward Warren, told the Washington Examiner he isn't too worried about her appeal to centrist members of his party.

"One way or another, we've got to make affordable healthcare and good medical care a reality for everyone, whether it's 'Medicare for all' or 'Medicare for all who want it,'" the IT professional said at the Buttigieg event in Spencer. "I hope that that can happen someday, even if it's not immediately after the next election."