Mainstream Democrats’ Performance in 2020 House Races Offers Lessons for 2022

Most of the research on what happened in the 2020 election has focused on the presidential race. This is understandable. It was a democracy-saving victory for the country. Our partner Catalist has a detailed analysis that looks at the electorate in aggregate and the presidential race specifically. This is an invaluable resource for understanding what happened in 2020.
But there are lessons to learn beyond what happened at the top of the ticket. The analysis here draws on voter file data from Catalist to understand what happened in two groupings of Congressional districts last year: districts where mainstream Democratic candidates were on the ballot and others where candidates hewed to the party’s left wing. Candidates were grouped as “mainstream” or “left-wing” based on endorsements from ideologically aligned groups. Only challengers (no incumbents) were included in this analysis. Please reference the bottom of this product for full methodological details.
Summary
By the overall results, 2020 was a tough year for Democrats in U.S. House races. Many strong Democratic challengers lost, while incumbents who were thought to be locks had narrow wins or even fell just short of keeping their seats. Ultimately, Democrats were left with a razor-thin majority to defend in 2022.
But new data from Catalist shows that mainstream Democratic candidates across a series of House districts increased their support by six points in 2020 over previous Democratic candidates from the same districts, while left-wing candidates increased their support by less than half a point. Mainstream candidates’ biggest gains were with emerging and enduring segments of Democrats’ coalition, including college-educated voters, Black Americans, and voters under 50. Mainstream Democrats did not win everywhere we’d hoped in 2020, but where they were on the ballot, they gave Democrats their best shot in a hard downballot election cycle.
Mainstream candidates’ relative gains and left-wing candidates’ stagnation offer insights about what happened in 2020 and a model for who Democrats should champion and how they should run in 2022. Candidates from the Democratic mainstream are clearly in the best position to defend the House majority in 2022.
Mainstream Democratic Candidates Surged in 2020 Compared to Previous Candidates.
Democrats were not as successful in House races as many expected in 2020. But where they did well compared to 2016, there was almost always a mainstream candidate on the ballot.
Last year, mainstream Democratic House candidates increased their support over Democratic candidates from the same districts in 2016 by around six points (41.6% to 47.3%). These findings are consistent with a recent Third Way analysis that found mainstream candidates were better able to approach Joe Biden’s district-level performances than left-wing candidates. Carolyn Bourdeaux in Georgia’s 7th Congressional District exemplified mainstream candidates’ surge. She won by three points in a district that Republicans carried by 20 in 2016. By contrast, left-wing Democratic candidates increased their support by less than half a point (47.1% to 47.5%). Previous Democratic candidates who ran in the same districts in 2016 did not uniformly align ideologically with the candidates who ran in 2020. Some mainstream candidates in 2020 were preceded by left-wing candidates in 2016, and the same goes for left-wing candidates last year. But the unmistakable correlation from Catalist’s data is that Democratic support surged in House races where a mainstream candidate was on the ballot.

The focus here is not on identifying why mainstream candidates gained more ground than left-wing candidates in 2020. But one potential explanation that can be ruled out is that mainstream candidates ran in friendlier districts. Biden lost the districts with mainstream House candidates on the ballot by two points and won those with left-wing candidates by two. One recent study suggested that moderates perform better than those from the ideological poles because they do not have the same mobilizing effect on opponents’ base voters—a theory we should further explore moving forward.
Mainstream Democratic Candidates Not Only Gained More Support, But They Gained More Support with Key Voter Segments.
Compared to Republicans’ increasingly monolithic voter bloc, Democrats’ diverse coalition is both a challenge and an opportunity. It can be a precarious federation of voters from different ideologies, races, age groups, and educational backgrounds. But when these voters come together, Democrats can’t be beaten.
In 2020, mainstream Democratic House candidates gained support over 2016 candidates across key segments of Democrats’ coalition. These gains were most pronounced with long-standing segments of the coalition, like Black Americans and voters under 50, but they also were evident with emerging components of the coalition like college-educated voters. By contrast, left-wing Democratic candidates had marginal gains or even lost ground with key voter groups that make up a winning Democratic coalition.

Mainstream candidates’ biggest gain by voter group was with college-educated voters. Compared to candidates who ran in the same districts in 2016, mainstream candidates gained ten points with college-educated voters in 2020. Mainstream candidates also gained ground with non-college voters, but more marginally, increasing support by three points. By contrast, left-wing candidates lost three points with non-college voters last year.
Looking at voters by race, mainstream candidates gained eight points with Black Americans and Asian Americans in 2020. They also gained five points with white voters, while left-wing candidates lost around half a point with them. Consistent with broader trends from 2020, neither mainstream nor left-wing candidates made significant progress with Latino voters. Mainstream candidates gained two points with Latinos compared to 2016, but left-wing candidates lost one point.
Mainstream candidates’ biggest gain by age was with those in the 40–49 age group, with these voters swinging nine points from 2016. But they also gained five points with voters under 30, while left-wing candidates lost two points with young voters compared to 2016 (and here the data runs completely counter to the accepted wisdom that to appeal to young people we must nominate a Bernie Sanders-style candidate).
Looking ahead, mainstream candidates’ momentum among key groups within Democrats’ coalition is a promising sign as we turn to the 2022 midterm election.
Mainstream Candidates’ Gains Provide Insights About What Happened in 2020 and a Model for 2022.
Mainstream Democratic candidates’ relative gains in House races offer important insights about what happened in 2020, but they also set up a model for how Democrats can protect their majority in 2022. Mainstream candidates are ascendant in House races, and they give Democrats their best shot at holding the chamber next year.
That is why Third Way has established Shield PAC, an organization that will champion moderate and mainstream Democratic House candidates in 2022 and inoculate them against claims that they belong to the “far left.” Shield PAC will deploy paid media campaigns in majority-making House races to help define these candidates as part of the Democratic mainstream and ensure their ideological positioning aligns with the candidates who performed best last time around.
Democrats have a diverse coalition, and it is broad enough to include candidates and voters from across the ideological spectrum. But Catalist’s data highlighted in this analysis makes clear that the Democratic House candidates with momentum right now hail from the party’s mainstream.
Conclusion
Mainstream candidates’ gains and left-wing candidates’ struggles in House races tell part of the story of 2020, and these trends also lay out a model for who Democrats should champion and how they should run in 2022. Mainstream candidates gained six points in 2020 compared to candidates who ran in the same districts in 2016, while left-wing candidates gained less than half a point. Mainstream candidates not only made broad-based gains, but they gained the most with key segments of Democrats’ coalition, including college-educated voters, Black Americans and Asian Americans, and voters under 50. Democrats benefit from their broad and diverse coalition, and one lesson from the last election is that mainstream candidates give the party its best shot at defending the House majority in 2022 and beyond.
Methodology
Democratic support estimates included in this analysis are based on Catalist data, which includes 15 years of voter registration records, supplemented by large-scale polling, modeling, and precinct-level election results to provide a detailed view of who voted in recent elections and how they voted. All support estimates in this analysis are two-way numbers (Democratic versus Republican).
Candidates were classified as “mainstream” and “left-wing” based on endorsements received by ideologically aligned groups. Mainstream candidates were aligned with the mainstream NewDem Action Fund. Left-wing candidates were aligned with at least one of the following groups: Our Revolution, Justice Democrats, or Brand New Congress. At this link, you can find a full list of districts included in this analysis.
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