WASHINGTON — When Leah Daughtry, a former Democratic Party official, addressed a closed-door gathering of about 100 wealthy liberal donors in San Francisco last month, all it took was a review of the 2020 primary rules to throw a scare in them.
Democrats are likely to go into their convention next summer without having settled on a presidential nominee, said Ms. Daughtry, who ran her party’s conventions in 2008 and 2016, the last two times the nomination was contested. And Senator Bernie Sanders of Vermont is well positioned to be one of the last candidates standing, she noted.
“I think I freaked them out,” Ms. Daughtry recalled with a chuckle, an assessment that was confirmed by three other attendees. They are hardly alone.
From canapé-filled fund-raisers on the coasts to the cloakrooms of Washington, mainstream Democrats are increasingly worried that their effort to defeat President Trump in 2020 could be complicated by Mr. Sanders, in a political scenario all too reminiscent of how Mr. Trump himself seized the Republican nomination in 2016.
How, some Democrats are beginning to ask, do they thwart a 70-something candidate from outside the party structure who is immune to intimidation or incentive and wields support from an unwavering base, without simply reinforcing his “the establishment is out to get me”’ message — the same grievance Mr. Trump used to great effect?
But stopping Mr. Sanders, or at least preventing a contentious convention, could prove difficult for Democrats.
He has enormous financial advantages —
already substantially outraising his Democratic rivals — that can sustain a major campaign through the primaries. And he is well positioned to benefit from
a historically large field of candidates that would splinter the vote: If he wins a substantial number of primaries and caucuses and comes in second in others, thanks to his deeply loyal base of voters across many states, he would pick up formidable numbers of delegates.
To a not-insignificant number of Democrats, of course, Mr. Sanders’s populist agenda is exactly what the country needs. And he has proved his mettle, having emerged from the margins to mount a surprisingly strong challenge to Hillary Clinton, earning 13 million votes and capturing 23 primaries or caucuses.
His strength on the left gives him a real prospect of winning the Democratic nomination and could make him competitive for the presidency if his economic justice message resonates in the Midwest as much as Mr. Trump’s appeals to hard-edge nationalism did in 2016. And for many Sanders supporters, the anxieties of establishment Democrats are not a concern.
That prospect is spooking establishment-aligned Democrats, some of whom are worried that his nomination could lure a third-party centrist into the field. And it is also creating tensions about what, if anything, should be done to halt Mr. Sanders.
Some in the party still harbor anger over the 2016 race, when he ran against Mrs. Clinton, and his continuing resistance to becoming a Democrat. But his critics are chiefly motivated by a fear that nominating an avowed socialist would all but ensure Mr. Trump a second term.
“There’s a growing realization that Sanders could end up winning this thing, or certainly that he stays in so long that he damages the actual winner,” said David Brock, the liberal organizer, who said he has had discussions with other operatives about an anti-Sanders campaign and believes it should commence “sooner rather than later.”
But to some veterans of the still-raw 2016 primary, a heavy-handed intervention may only embolden him and his fervent supporters.
R. T. Rybak, the former Minneapolis mayor who was vice chairman of the Democratic National Committee in 2016, complained bitterly about the party’s tilt toward Mrs. Clinton back then, and warned that it would backfire if his fellow mainstream Democrats “start with the idea that you’re trying to stop somebody.”
If the party fractures again, “or if we even have anybody raising an eyebrow of ‘I’m not happy about this,’ we’re going to lose and they’ll have this loss on their hands,” Mr. Rybak said of the anti-Sanders forces, pleading with them to not make him “a martyr.”
The good news for Mr. Sanders’s foes is that his polling is down significantly in early-nominating states from 2016, he is viewed more negatively among Democrats than many of his top rivals, and he has already publicly vowed to support the party’s nominee if he falls short.
“Bernie Sanders believes the most critical mission we have before us is to defeat Donald Trump,” said Faiz Shakir, Mr. Sanders’s campaign manager. “Any and all decisions over the coming year will emanate from that key goal.”
Or, as former Senator Claire McCaskill of Missouri put it: “One thing we have now that we didn’t in ’16 is the uniting force of Trump. There will be tremendous pressure on Bernie and his followers to fall in line because of what Trump represents.”
But Mr. Sanders is also taking steps that signal he is committed for the duration of the race — and will strike back aggressively when he’s attacked. On Saturday his campaign
sent a blistering letter to the Center for American Progress, a Clinton-aligned liberal think tank, accusing them of abetting Mr. Trump’s attacks, of playing a “destructive” role in Democratic politics, and of being beholden to “the corporate money” they receive. The letter came days after a website aligned with the center aired a video highlighting Mr. Sanders’s status as a millionaire.
With other mainline party leaders, he is offering more honey than vinegar.
Last month, for example, he used his first trip to Iowa as a 2020 candidate to quietly meet with Jeff Link, a veteran party strategist, and Patty Judge, the former state agriculture secretary, to discuss rural policy and politics, according to a Democrat familiar with the meeting. Mr. Sanders’s campaign also reached out to Randi Weingarten, the head of the American Federation of Teachers and a top Clinton ally in 2016, to have her join them at what they called an “Ohio workers town hall” on Sunday.
“If anybody thinks Bernie Sanders is incapable of doing politics, they haven’t seen him in Congress for 30 years,” said Tad Devine, Mr. Sanders’s longtime strategist, who is not working for his campaign this year. “The guy is trying to win this time.”
But such outreach matters little to many Democrats, especially donors and party officials, who are growing more alarmed about Mr. Sanders’s candidacy.
Mr. Brock, who supported Mrs. Clinton’s past presidential bids, said “the Bernie question comes up in every fund-raising meeting I do.” Steven Rattner, a major Democratic Party donor, said the topic was discussed “endlessly” in his orbit, and among Democratic leaders it was becoming hard to block out.
“It has gone from being a low hum to a rumble,” said Susan Swecker, the chairwoman of Virginia’s Democratic Party.
Howard Wolfson, who spent months immersed in Democratic polling and focus groups on behalf of former Mayor Michael R. Bloomberg of New York, had a blunt message for Sanders skeptics: “People underestimate the possibility of him becoming the nominee at their own peril.”
The discussion about Mr. Sanders has to date been largely confined to private settings because — like establishment Republicans in 2016 — Democrats are uneasy about elevating him or alienating his supporters.
The matter of What To Do About Bernie and the larger imperative of party unity has, for example, hovered over a series of previously undisclosed Democratic dinners in New York and Washington organized by the longtime party financier Bernard Schwartz. The gatherings have included scores from the moderate or center-left wing of the party, including Speaker Nancy Pelosi of California; Senator Chuck Schumer of New York, the minority leader; former Gov. Terry McAuliffe of Virginia; Mayor Pete Buttigieg of South Bend, Ind., himself a presidential candidate; and the president of the Center for American Progress, Neera Tanden.
“He did us a disservice in the last election,” said Mr. Schwartz, a longtime Clinton supporter who said he would support former Vice President Joseph R. Biden Jr. in this primary.
