Ghosts of Elections Past haunt the 2020 Democratic primary race

Unintentionally or not, Warren’s recent spat with Sanders over a reported disagreement about female electability has raised the ghosts of the 2016 Democratic primary, stoking the resentments felt particularly by women who supported Clinton, because they believe he wounded their candidate ahead of her matchup with Trump.

And the Ghosts of Elections Past were louder than ever on Tuesday, when Clinton declared in an excerpt from a new documentary that “nobody likes” Sanders. In an interview about the documentary in the Hollywood Reporter, Clinton denounced “his online Bernie bros and their relentless attacks on lots of his competitors, particularly the women.” Asked whether she would endorse and campaign for Sanders if he wins the nomination, Clinton said, “I’m not going to go there yet.”

In the eyes of Sanders’ supporters, though, Clinton won the nomination by navigating a process heavily tilted in her favor by the Democratic National Committee.

Four years after the Clinton-Sanders nomination fight, Warren and Sanders are battling for liberal voters. Warren downplayed her differences with Sanders as she campaigned in Iowa last weekend, but the Pandora’s box of 2016 was already open, as voters openly grappled with thorny questions about sexism, politics, and whether history could repeat itself in 2020.

It has all brought the volatility of 2016 back to the fore, creating a moment that threatens to pull Warren back into a divisive intraparty fight at a time when she is calling for unity. It also is one that could help rally female voters, according to interviews conducted in Iowa, at a time when Warren is the only woman left in the race’s top tier and seems increasingly willing to emphasize her gender.

“Look, I am convinced we can do this together — this is not 2016,” Warren said on Saturday in response to Keith’s question, saying women had already powered historic victories in the midterms. She assured the voter she and Sanders are friends.

But she still let the specter of that election hover in the air, like a warning.

“I was out there in 2016, and I know how many other people were too,” Warren said. “It didn’t work, but it was a big, big wake-up call for a lot of people.”

Much of some voters’ enduring fixation with 2016 is well beyond Warren’s control, as is the timing of any Clinton comment on the matter. But last week, Warren briefly referred to 2016 herself, responding to a report that Sanders volunteers had been instructed to deride her supporters by saying Democrats could not afford to repeat the “factionalism” of the 2016 primary and chiding Sanders for not reaching out to all Democrats.

In the following days, after CNN reported that Sanders had told her privately that a woman could not win the presidency, Warren stuck by the story and parlayed it into an argument for the electoral potency of a female presidential candidate.

“Since Donald Trump was elected, women candidates have outperformed men candidates in competitive races,” Warren said.

The moves come as Warren has lost a series of high-profile progressive endorsements to Sanders. But they could help her dial up support from another bloc of voters: those who supported Clinton.

“She needs to draw a contrast between her and Bernie Sanders,” said Patti Solis Doyle, Clinton’s campaign manager in 2008.

She added: “She has found something here in embracing gender issues and embracing, taking advantage of what happened to Hillary in 2016. Don’t let it happen again, let’s not do this again to another woman candidate — it’s a strong message.”

Warren’s push on gender represents a slight shift in her rhetoric. From the beginning of her campaign, she has avoided appeals to women voters as overt as one Clinton campaign slogan, “I’m with her,” or Senator Kirsten Gillibrand’s short-lived and women-focused presidential campaign last year.

Instead, Warren has woven policies about maternal health and universal child care more subtly into her pitch and dotted her campaign with major speeches about female activists like the black washerwomen in Atlanta who led a major strike in 1881, or the immigrant women who sparked the Bread and Roses strike in Lawrence. That strategy is aimed at trying to make inroads with women of color, who are a crucial pillar of the Democratic electorate.

Some female voters in Iowa this week suggested that her decision to take on gender more directly has drawn new attention to her.

Keith, for example, decided this week to back Warren in part because she thought she and Warren have faced the same kind of sexism. “Maybe it’s risky to talk about it with men,” Keith said, “but I will tell you I think maybe for women, women are waiting to have this conversation.”

Carlene Russell, 68, a retired dietitian who went to see Warren speak in Des Moines on Sunday, said the whole spat with Sanders had improved her view of Warren.

“The injustice that a woman is being questioned that she could run and win the election, that really bothered me,” Russell said, “and in my viewpoint, that brought Sanders way down.”

And it left some of Warren’s supporters feeling frustrated as some Sanders supporters lobbed snake emojis and gendered epithets at Warren online. Jaqui Giltner, a voice teacher who voted for Sanders in 2016, said she grew disillusioned when she saw similar behavior after the primary. “They act as though they’re what’s best for women, and not women,” Giltner said.

Sanders made other statements over the weekend that riled up some voters, including telling New Hampshire Public Radio that gender is still an obstacle for a female politician — “Everybody’s got their own sets of problems,” he said.

But for Warren, there are considerable risks to evoking the painful divisions of 2016 even briefly — especially at a time when she is trying to convince voters she is well positioned to unify the party.

“Any little petty squabbles from 2016, I don’t wanna hear it,” said Aimee Allison, the founder of She the People. “I am a 50-year-old black woman, I’m the base of the base, I don’t want to hear it!”

It is not clear how important gender is, even to women voters — and it is possible that, by emphasizing it, she could hurt her standing with male voters. A Suffolk University/Boston Globe poll of New Hampshire voters found Warren’s support had dropped with male voters, to just 4 percent of them, compared to 13 percent of men in an earlier poll.

Still, some Democrats — particularly those who supported Clinton — believe the last election is well worth examining.

“The divisiveness of the 2016 primary campaign is seared in many Democrats’ memory, and many believe it hurt Hillary in the general election,” said Neera Tanden, a former Clinton aide who is now president of the Center for American Progress, a progressive think tank. “That factionalism had terrible consequences, and so reminding people of that problem, especially when everyone is focused on electability, is important.”

Jess Bidgood can be reached at Jess.Bidgood@globe.com. Follow her @jessbidgood.