Will Democrats’ Bitter Primaries Hurt Them When It Matters Most?

Healing those wounds is no small challenge. Democratic divisions have been front and center this year. (Losing another presidential election to Donald Trump will do that to a party.) Some of the divides are over ideology and policy; in last week’s Michigan Senate primary , Abdul El-Sayed, a progressive supporter of Medicare for All, narrowly beat Rep. Haley Stevens, a pro-Israel centrist. Others—including Tuesday’s Wisconsin governor primary, in which the moderate David Crowley even more narrowly defeated Francesca Hong, a democratic socialist—are about which candidate is better equipped against Republicans or is advocating exciting new ideas.

Divisive primaries happen for a reason; they can help parties work out policy disagreements or stress-test candidates’ mettle. But bridging those divides isn’t easy, and this year’s primary season could haunt Democrats in key races this fall. Political science research suggests that longer and more competitive primaries can ultimately cost the party’s nominee votes in the general election. Only one candidate can win, after all, which leaves plenty of room for hurt feelings among the losing contender’s supporters—some of whom might choose to stay home rather than vote for someone who wasn’t their first choice.

Several of this year’s bitterest primaries so far also involved more than two candidates; this can split the vote such that no one gets a majority. That’s what happened in Michigan (where El-Sayed won with 49 percent of the vote) and in Wisconsin (where Crowley emerged victorious despite earning less than 40 percent). A 2024 study that looked at both parties’ House, Senate, and gubernatorial primaries from 2010 to 2022 found that candidates who win only a plurality of the vote tend to underperform in general elections relative to expectations. For plurality winners in closely divided parts of the country (like, say, Michigan and Wisconsin), “this translates into a reduced likelihood of winning,” the paper concludes.

Acrimonious primaries can hurt victorious candidates in other ways, too. Sometimes the positions they take to court their party’s base actively repel the wider pool of voters, whose support they may need in the fall. Contentious primaries often bring media scrutiny, which can expose damaging truths about a candidate’s past; Hong’s years-old criticisms of policing and Thanksgiving probably helped doom her in Wisconsin. Extended primaries also eat up resources. Dollars spent on attack ads against a fellow Democrat over the summer can’t be spent on attack ads against a Republican in the fall.

But just because divisive primaries can be fatal in general elections doesn’t mean they have to be. Democrats have a choice about whether to let the wounds of primary season hamstring their nominees. How the winning and losing candidates—and those candidates’ supporters—treat each other over the next few months will help determine whether those divides heal in time for November.

There’s already evidence that at least some Democrats are trying to mend fences.