For the past three election cycles, 538 has tracked key progressive groups' endorsees to get a sense of Democrats' intraparty dynamics following the 2016 presidential primary, which drew out sharp ideological factions and spurred an ambitious progressive movement working to make its mark on the party. For example, in 2018, now-Reps. Alexandria Ocasio-Cortez and Ayanna Pressley shocked the political world by unseating 20-year incumbents in Democratic primaries. In 2020, fellow progressives Jamaal Bowman and Cori Bush won their own upsets against long-serving members. But in 2022, fewer progressives were successful in unseating incumbents. One was Oregon's Jamie McLeod-Skinner, who defeated Rep. Kurt Schrader despite Biden's endorsement of the incumbent, but went on to lose in November.
Today's races may not answer whether progressives candidates this year will unseat incumbents — none of the races we're watching tonight pit incumbents against notable progressives. Has the progressive caucus's appetite to challenge incumbents cooled as they worked with the rest of their party to help Biden pass his legislative agenda? Or are they preoccupied preparing to play defense against expected challengers of their own?
At least one incumbent on a primary ballot today notably doesn't have a progressive challenger: In Texas's 28th District, progressives have passed on a third attempt to unseat Rep. Henry Cuellar, after backing attorney Jessica Cisneros in both 2020 and 2022. In those cycles, progressive groups attacked Cuellar's conservative positions on issues like abortion and gun control, but Cuellar narrowly defeated Cisneros each time. Although the state director of the Working Families Party has criticized Cuellar this cycle, no progressive challenger has emerged, and today he will coast to the nomination.
Of course, progressive candidates aren't just trying to replace incumbent Democrats who they think are out of step with the modern party. They're running in primaries for open and competitive races all over the country, like California's Senate contest and California's 40th District race, where Democrats hope to unseat Republican Rep. Young Kim in November. To get the full picture of the progressive wing's electoral strategy and success rates in 2024, we're once again tracking candidates who have received endorsements from any of the following key progressive groups: Justice Democrats, Indivisible, the Working Families Party, the Congressional Progressive Caucus PAC, the Sunrise Movement, and Sen. Bernie Sanders.
Throughout the evening, we'll share tables like this one with updated results as we find out how progressives (and other candidate groupings in both parties — like women and Trump endorsees) fare in today's primaries.
—Meredith Conroy, 538 contributor