AMONG DEMOCRATS, MOST VOCAL FACTIONS DISMISS CENTRISTS

billionaire who wants to “keep a rigged system in place.”

If Bloomberg’s views grate on many Democrats, allies see it as a distinctive trait in a diffuse primary. Howard Wolfson, an adviser to the former mayor, said the current Democratic field seemed to invite a competitor closer to the center.

“We believe that there is a clear and sufficiently wide lane for a pragmatic candidate, and that the progressive lane is really crowded,” Wolfson said. “The pragmatic lane is relatively free.”

Polls suggest that somewhere between a third and half of Democratic voters see themselves as moderates, though the label is vague enough to cast doubt on the group’s cohesion.

That bloc, these candidates and their advisers acknowledge, could lose influence if a herd of self-styled pragmatists end up stampeding into the Democratic contest, atomizing the center even as progressive competitors carve up the left. It is also highly uncertain that Democrats, who celebrated the election of many women and candidates of color in 2018, would turn quickly in 2020 to nominating a white man with narrower governing ambitions.

In the early primary states, much of the action so far has focused on proudly liberal, potentially history-making candidates, including Warren and Sens. Kamala Harris of California and Kirsten Gillibrand of New York.

But former Gov. John Lynch of New Hampshire, a centrist Democrat, said he saw a clear opening for a candidacy pitched at the middle, one that was attentive to matters like climate change but also sensitive to deficits and debt. Lynch named Biden and Bloomberg as the two most compelling possibilities.

“I’d like to see somebody come in and make the case for electing a more moderate candidate,” Lynch said, “and I believe that if the Democrats want to beat President Trump, their best bet is electing somebody in the middle.”

Lynch cautioned that the chances for an avowed moderate would fade if too many people compete for the label: “If there are a couple of moderates, then they are going to take share away from each other.”

The road to the Democratic nomination would likely be fraught for any moderate, especially one who would not break a historic barrier by virtue of identity, as Barack Obama did in 2008. To some Democrats, a more centrist message might too closely echo Hillary Clinton’s unsuccessful 2016 campaign, which left many in the party determined to focus on mobilizing the left over pursuing the middle. And the most vocal Democratic factions have shown little interest so far in settling for something other than a liberal champion, on issues from taxation and business regulation to criminal justice and gender equality.

Warren has emerged as something of an intellectual pacesetter for liberal Democrats on economic issues, including her proposal to tax the wealth of households with assets greater than $50 million at a rate of 2 or 3 percent per year. And Harris, whose signature proposal has been a more conventional middle-class tax cut, called in a CNN interview for the elimination of private health insurance as part of a shift toward a “Medicare for all” single-payer health care.

Several other liberals of differing stripes have or are likely to join the race soon, including Sens. Bernie Sanders of Vermont and Cory Booker of New Jersey; others are considering it seriously, like Sens. Sherrod Brown of Ohio and Jeff Merkley of Oregon.

Polls of Democratic voters offer mixed signals about how liberal they want their nominee to be. There is no question the party has moved leftward: The Gallup Poll found this month that for the first time in decades, a majority of Democrats describe themselves as liberal, while just 34 percent now call themselves moderate. And taxing the rich is broadly popular, with a sizable majority of Americans believing wealthy people and corporations pay too little to the government.

“People have grown more liberal and more willing to call themselves liberal,” said Lydia Saad, a senior editor at Gallup, cautioning that ideology did not necessarily predict voting behavior: “The public is very fungible in terms of who they will accept as a leader, based on things that seem to go beyond ideology.”

Arkadi Gerney, a Democratic strategist who runs the Hub Project, a liberal advocacy group that has focused heavily on taxes, said that intensive issue polling had consistently found powerful support for raising taxes on the wealthy, not just among Democrats but also among working-class white voters in Trump’s base.

“The thing that was consistently the most popular in those experiments was: raise taxes on the rich,” Gerney said. “It is tapping into anger that a lot of people have.”

Yet there are also signs of hesitation among some Democrats about shifting left. A January study by the Pew Research Center found that 53 percent of Democrats want the party to become more moderate, compared with 40 percent who want it to grow more liberal. A Kaiser Family Foundation poll found that while single-payer health care is hugely popular among Democrats, half of the party’s voters want House Democrats to prioritize improving the Affordable Care Act over passing Medicare for all legislation.

Biden and Bloomberg, both 76, have defended their relatively centrist approach in recent weeks, calling it the best way to win and govern. Biden described working with Republicans as a first principle at a Washington event last week; without that spirit, he said, “I don’t know how you get anything done.” And Bloomberg swatted at the left more bluntly in New Hampshire.

Either man could seek to monopolize the party’s moderate constituencies: Biden through his stature as a two-term vice president, Bloomberg by spending his multibillion-dollar fortune. Both have already faced criticism for having supported aggressive policing and crime policies; Biden has expressed some regret for his record, while Bloomberg has defended his.

If Biden and Bloomberg do not run, there could be no wellknown candidate positioned near the center. That could create space for a lower-profile moderate to emerge.

Two wild-card Democrats who could run toward the middle, strategists say, are Sen. Amy Klobuchar of Minnesota and Beto O’rourke, the former Texas Senate candidate. Both are widely liked by liberals but have shown a preference for conciliation and compromise. It is unclear how they would present themselves, ideologically, if they run.

Matt Bennett, vice president of centrist Democratic group Third Way, said that for any moderate to catch fire in 2020, it would require more than offering toned-down versions of liberal candidates’ policies and “eat your peas” lectures about government debt.

“They’re going to have to be aspirational, optimistic, future-oriented,” Bennett said. “Like Bill Clinton, like Barack Obama.”