DES MOINES — Hours ahead of the final debate before the Iowa Democratic caucuses, a long-simmering question within the party was thrust to the forefront: Can a woman defeat President Trump?
It started Monday when a CNN report outlined a 2018 one-on-one meeting between Senator Bernie Sanders of Vermont and Senator Elizabeth Warren of Massachusetts in which he allegedly told her that a female candidate could not defeat Trump in November. Warren later confirmed the report, saying such a conversation had taken place.
Sanders has heatedly denied making that statement during the discussion at Warren’s home in Washington, contending that he merely outlined what he said would be Trump’s efforts to defeat another female candidate.
It was also unavoidable that the dispute would explode, as it played on the still-raw wounds of the 2016 campaign and continued consternation by some sympathetic to Hillary Clinton that Sanders and his backers were insufficiently supportive of her in that contest.
Less than three weeks before the first voting takes place in Iowa, a worry that voters long have contended with broke into the open: With Democrats so eager to defeat a president they see as a racist, sexist bully, is the safest bet to defeat him a man?
Former vice president Joe Biden elliptically referred to that calculation earlier this month when he noted that Clinton faced ‘‘unfair’’ sexism during her campaign.
‘‘That’s not going to happen with me,’’ Biden said.
The sharp break in recollections by Sanders and Warren were particularly unnerving for the liberal wing of the party, fearful that divisions between the two most leftward candidates would usher in a moderate nominee.
‘‘Too much is at stake right now for mutual destruction,’’ said Rebecca Katz, a liberal strategist who plans to vote for Warren but also likes Sanders.
Others underscored the personal impact of the disputed words.
‘‘Yes, many people have told me a woman can’t win in 2020,’’ tweeted author and columnist Connie Schultz, who is married to Senator Sherrod Brown, an Ohio Democrat who considered a presidential run. ‘‘This is fear speaking, & it has sparked meaningful conversations. But a woman hears this differently when she is the one who is running. It feels personal because it is. Can we please not lose sight of this difference?’’
The conflict has effectively amplified what has been an impassioned, if somewhat below the radar, conversation in Democratic circles. A year ago, a record number of women were sworn into Congress. Nancy Pelosi, the California Democrat and the first female House speaker, was back in power. And activists were excited about a new generation of women joining the presidential contest.
Since then, though, two men — Sanders and Biden — have ascended to the top of the polls, joined in some of them by former South Bend, Ind., mayor Pete Buttigieg.
Several female candidates failed to gain traction and ended their campaigns, including Senator Kirsten Gillibrand, Democrat of New York. These trends have been concerning to many Democratic women, who feel their party is not giving all candidates a fair shake.
‘‘Almost everyone running represents someone that hasn’t been elected before,’’ said Christina Reynolds, vice president of communications at Emily’s List. ‘‘We’re hanging that on the women.’’
Sanders and Warren have shown little appetite to continue their extraordinary dispute; neither candidate broke from their preparations for Tuesday’s debate to elaborate on their Monday comments.
But the nature of the topic and the timing of the dispute virtually ensured its continued prominence. Sanders and Warren joined four other candidates at the debate here in Des Moines.
It was expected to be the final time the major contenders will appear together on national television before Iowa holds the first nominating contest on Feb. 3. And it was the first joint public appearance for Sanders and Warren since their relationship took a contentious turn.
The clash centered on their differing accounts of a private conversation about gender and politics at Warren’s home in 2018, the details of which were first reported by CNN.
‘‘I thought a woman could win; he disagreed,’’ Warren said in a statement providing her recollection of the discussion.
Two people with knowledge of the conversation, however, told The Washington Post that Warren had asked Sanders whether he thought a female candidate could defeat Trump, and Sanders had replied with his worry about Trump’s tactics. The two spoke on the condition of anonymity to reflect private conversations.
In a statement issued Monday, Sanders said it is ‘‘ludicrous to believe that at the same meeting where Elizabeth Warren told me she was going to run for president, I would tell her that a woman couldn’t win.’’
Warren, in a statement issued later, disagreed with his recollection.
‘‘I thought a woman could win; he disagreed,’’ she said, adding: ‘‘I have no interest in discussing this private meeting any further because Bernie and I have far more in common than our differences on punditry.’’
Monday’s exchange followed a flare-up less than 24 hours earlier, when Warren accused Sanders of ‘‘sending out volunteers to trash me,’’ following a report in Politico that a Sanders campaign script instructed volunteers to tell voters leaning toward Warren that her popularity was limited to the rich and educated — effectively denigrating her electability.
Sanders sought to distance himself from that controversy, saying, ‘‘We have hundreds of employees. Elizabeth Warren has hundreds of employees. And people sometimes say things that they shouldn’t.’’ His campaign declined to comment further.
The turbulence occurs amid two colliding changes in the first-voting state. Sanders has gained steam in Iowa since the fall, polls show, and narrowly occupied the top spot in one recent survey amid signs that Warren has faded. Biden, Buttigieg, and the two more liberal candidates are tightly bunched overall.
At the same time, Warren has been putting more emphasis on her gender, seeking to reenergize the anti-Trump passion that gave rise to women’s marches and a high turnout of female voters in 2018.