Electability over ideology: Takeaways from the 2026 primaries

Over the years, congressional districts have become less competitive, with many becoming increasingly safe for one party or the other. As a result, interest in studying congressional primaries has increased, since the dynamics of congressional primaries—who runs, who wins, and the ideological fissures within each party—tell us a great deal about the future of government. Very few incumbents lose their primaries: In 2026, 13 lost (as of early September); in 2024, only four lost; and in 2022, 14 lost. Nonetheless, many members of Congress fear being “primaried.”

The fear of facing a primary challenge can lead incumbent representatives and senators to anticipate potential threats to their seats and adjust their behavior accordingly. This dynamic is one factor that researchers have identified as contributing to the political polarization that has become a prominent feature of contemporary American politics.

Qualitative research by Elaine Kamarck and James Wallner found that members of Congress worry about the possibility of a primary challenge, believe contested primaries can damage their prospects in the general election, overestimate the significance of successful primary challenges, and maintain that changing their behavior can help prevent or defeat a challenger. A December 2024 qualitative study by J.D. Rackey and Michael Thorning reached similar conclusions after interviewing members of Congress. Their research found that primary elections can influence both the congressional agenda and members’ voting decisions, while also shaping how members communicate with their constituents. In particular, members may adjust their messaging and tone in an effort to prevent or respond to primary challenges.

Taken together, this research suggests that primary challenges, whether actual or merely anticipated, can influence the behavior of members of Congress. By shaping how representatives and senators approach legislation, voting, and communication with their constituents, the prospect of a primary challenge can also influence the broader political environment within each party’s House and Senate caucuses and ultimately affect the range of issues and policies considered by Congress.

In the past, we have studied the universe of congressional candidates in each party. For the 2026 cycle, we decided to concentrate on primary candidates from 33 congressional districts and 10 Senate races. We chose these districts and states because they were the most likely to change parties, making them the races where both Democrats and Republicans would be most likely to field their strongest candidates. To build our universe of competitive races, we drew on the Cook Political Report’s Partisan Voting Index (PVI), selecting districts with a PVI between D+2 and R+2. Because redistricting later pushed several initially qualifying districts outside that range, the composition of our competitive-race universe shifted over the course of the project, which began in January 2026. We ended up with a sample of 300 candidates: 127 Democrats, 119 Republicans, and 54 third party/independent candidates.

This marks the sixth iteration of the Brookings Primaries Project, following earlier studies in 2014, 2016, 2018, 2022, and 2024. As in past years, we developed a coding sheet to systematically evaluate candidates. Throughout the 2026 primary season, a team of coders reviewed the websites, social media accounts, and public interviews of all 300 candidates who appeared on their party’s primary ballot in states and districts that fit our criteria for competitiveness. We gathered data on demographic characteristics, policy positions, and overall ideology. To preserve inter-coder reliability, the team met regularly to discuss findings, resolve discrepancies, and ensure consistent candidate characterizations.

Candidates running in close congressional primaries are mostly white men with higher levels of education. Nearly 72% of the candidates were men and 28% were women, a breakdown similar to what we found in previous years when we studied the entire universe of candidates. In our 2026 sample, however, women won at the same rate as men—a change from the previous cycle, when men won at a higher rate. With all the attention paid this year to finding candidates who are “authentic” and can talk to the average voter, the fact remains that this pool of candidates includes very few candidates whose highest level of education is a high school diploma (nearly 8% of the sample) and many candidates with advanced degrees (almost 46%).

In past studies we have conducted of all primary voters, more of the African American candidates were Democrats than Republicans. In this sample, however, Republicans slightly outnumbered Democrats among African American candidates—10.1% to 8.7%. Among Latino candidates, Democrats had a slight edge—13.4% to 7.6%. And, as in past years, more women ran in Democratic primaries than in Republican ones—37.8% to 23.5%.

Primaries test the strength of factions within a political party: A faction is strong if many candidates run under its banner and if they win. So, by looking at these candidates’ websites, social media, press coverage, and whether they were endorsed by a part of the party’s establishment, we were able to discern the ideological preferences of most candidates within their party. Some of these differences are small and require judgment calls. For instance, MAGA/Trump conservatives share many issue positions with mainstream conservatives; the difference lies in the degree to which the MAGA conservatives tout Trump and the MAGA movement. Among Democrats, many progressives hold similar positions to democratic socialists on certain issues, but they don’t call themselves democratic socialists, nor do they tend to highlight the DSA in their campaign materials.

As Table 1 illustrates, in both parties, more mainstream or centrist candidates won their primaries in our selected races; MAGA/Trump conservatives won just over a quarter of their races (26.7%), and progressive candidates on the Democratic side won less than a fifth of their races (17.8%). Out of five DSA candidates, only one won his primary—William Lawrence of Michigan, who was a DSA member until July 2026, when he allowed his membership to lapse in order to unite the party.

This outcome was to be expected in competitive races, since voters tend to be more sensitive to electability there than in safe districts. Still, there are small differences between the parties. A 2024 study by Northwestern University’s Institute for Policy Research found that the two parties’ voters view electability differently: Democratic primary voters tend to interpret ideological moderation as a sign of electability, while Republican voters draw more heavily on candidates’ fundraising.

But just because the most far-right and the most far-left factions of the two major parties don’t win primaries as often as more mainstream candidates, it doesn’t mean they aren’t important. As we’ve seen in the 119th Congress, a motivated faction such as the Freedom Caucus can stand in the way of legislation even when a majority of Congress supports it.

Although it is difficult to say how important endorsements are in determining outcomes, Trump endorsed 26 out of the 119 Republicans we looked at, and almost all of them (over 92%) won. Of course, 12 of these were incumbents, and as we’ve seen year after year, incumbents almost always win their primaries. On the Democratic side, only 10 candidates received the endorsement of a high-profile progressive like Sen. Bernie Sanders (I-Vt.), though six of them won their primary races.

We also attempted to determine which issues were widely discussed on the campaign trail. Not surprisingly, there were some major differences between candidates depending on party. (Note: We did not code for candidate positions on data centers, since the issue emerged as a major one late in the primary season. However, our colleagues Nicol Turner Lee and Darrell West have studied the issue as of August.)

Issue No. 1 is, of course, the economy, especially the cluster of issues known as “affordability.” It is the Achilles heel of the Republican Party heading into the November elections, which may explain why it was largely overlooked by Republicans: Only 23.5% defended the current administration’s actions on affordability, and none acknowledged any shortcomings in the administration’s handling of the issue. By contrast, nearly 56% of Democrats addressed inflation, with the vast majority criticizing the Trump administration for its inability to tackle a major campaign concern that had helped propel Trump to victory. Democrats will likely seek to emphasize affordability heading into the general election, as voters continue to feel the effects of rising prices at the grocery store and the gas pump.

Some candidates have already addressed it in the primaries. Rebecca Bennett, a Democrat who is running to represent New Jersey’s 7th Congressional District, emphasized in her campaign materials that “from childcare to groceries, it feels like the price of everything has gone up. Rebecca’s family knows what it’s like to deal with rising prices, and she knows that families across our district are feeling it too. It’s time for both parties to work together to make life in New Jersey more affordable for all of us.” Expect more language like this from Democrats looking to demonstrate that they understand the crisis and, unlike some of their opponents, are willing to discuss it.

Another impactful issue for Democrats was health care. Ninety-four percent of Democratic candidates addressed health care, an issue that was especially important in helping them take back the House in 2018. Nearly 60% of Democratic candidates wanted to expand, reform, and protect the Affordable Care Act, Medicare, and Medicaid, while another 32% advocated Medicare for All. Medicare for All, a rallying point for the party’s left flank, remains a minority view among candidates in competitive races, meaning Democrats would face an uphill battle on the issue if they regain the majority.

Nearly half of Republicans ignored health care, and among those who talked about it, most were concerned with controlling spending.

Immigration has been the most salient issue in the two years since the last national election, as evidenced by the fact that very few candidates in swing districts could ignore it. Among the Democrats, the vast majority staked out positions supporting comprehensive immigration reform. Interestingly, though, the few who took more conservative positions did well. At the other end of the spectrum, none of the Democratic candidates supported open borders, although Republican political ads on the issue would suggest otherwise. Ironically, the one candidate in a swing district who did support open borders ran in the Republican Senate primary in New Hampshire: Tom Alciere, an extreme libertarian.

As Table 3 shows, most of the Republicans running supported Trump’s hard line on the border, expressing support for securing the border, building the wall, and deporting undocumented immigrants. One candidate called for requiring all elected officials in the House and Senate, as well as mayors, to be born in the city, town, state, and country they represent, and to “pledge that they will strive to promote legal immigration and closed borders, to preserve our history and culture of the United States of America.”

However, given the Trump administration’s controversial deportation policies, we looked for statements from these candidates about deportation. As Table 4 illustrates, slightly more than half (52.9%) of Republican candidates running in competitive districts did not discuss deportations at all. Many of the others (42%) expressed support for Trump’s positions. Far more Democrats, meanwhile, expressed positions critical of the administration’s deportation policies.

On issues of law and order, most Democrats either supported law enforcement broadly or called for police reform—as illustrated in Table 5. The most significant finding here, again in contrast to Republican arguments, is that not one of 127 Democratic candidates used the phrase “defund the police” during this campaign cycle. Democratic candidates, especially those running in competitive districts, appear to have understood how unpopular that position was. Nearly all the Republicans expressed strong support for the police.

Like deportations, positioning on the U.S. role in supporting Israel emerged as a more powerful issue in the 2026 primaries than in previous elections. The two parties differed sharply, with more Republicans than Democrats offering unconditional support for Israel. However, a sizeable number of Republicans also avoided the issue altogether. Democrats were much more critical: A sizeable share (over 24%) took the most hardline position against Israel, while others supported both Israel and humanitarian aid to Gaza.

On Ukraine, the parties’ positions were reversed. While a majority of candidates in both parties avoided the issue, Democrats were far more supportive of military and economic aid for Ukraine than Republicans were. It remains to be seen, however, if this is a permanent position for the Republican Party, since Trump has repeatedly shifted his stance on Ukraine in his second term, and most Republicans are likely taking their cues from him.

There were some issues that the 2026 candidates simply ignored, with fewer than 40% addressing them on the campaign trail. Some are issues that are not their party’s strong suit. Democrats, historically identified as the party of big spenders, do not talk much about deficit spending. Few Democrats addressed critical race theory, perhaps reflecting the political liabilities associated with the issue.

Neither Democrats nor Republicans spent much time talking about the events of Jan. 6—even though President Trump himself continues to revisit the event.

Republicans don’t spend much time on climate change, preferring to talk about energy production instead. Nor do they spend much time discussing prescription drug costs or inflation—two issues which will likely dog the Republican Party into November. Few Republicans talk about Israel despite the war that’s been going on since Oct. 7, 2023. And few Republicans talk about critical race theory, probably because Democrats have also largely stopped discussing it.

As the two parties move into the general election, the primary season has offered a few lessons.

First, the hype surrounding the Democratic Party’s purported resurgence of left-wing strength may be greater than the underlying evidence suggests. There were only five DSA candidates in competitive districts, and only one of them, William Lawrence, won his primary. In another study, Elaine Kamarck, Riana Mahtani, and Gabriel Kraemer found that democratic socialist candidates in general were few and far between and have yet to show that they can win outside the bluest districts.

Democrats in these competitive districts, at least, have lost their penchant for themes that are wildly unpopular. Few, if any, candidates talk about open borders, and no one talks about defunding the police. The final hot issue—policy toward transgender individuals—Democrats deal with by giving general support to the LGBTQ+ community, while steering clear of specifics like trans women competing in girls’ sports.

Looking ahead to the next Congress, where Democrats have an opportunity to take control, two issues will likely divide the Democratic caucus: health care and aid to Israel.

Among the Republican candidates, those categorized as MAGA tended to win less often than conservative Republicans and moderate Republicans did in our selected races. Whether this is a general weakening of the movement or a reaction to being tied too closely to an unpopular president is unclear. In the final days of the 2026 primary season, Trump seemed determined to pursue policies, tariffs, and the war in Iran that most voters believe contribute to the affordability crisis. Rather than adjust his policies to help his party, he seems, in fact, to be doing the opposite.

Midterm elections tend to be important markers for determining when a president becomes a “lame duck.” They often signal the need for a reset for the losing party. In 1995, President Bill Clinton made significant changes after his party’s massive 1994 midterm defeat. It remains to be seen whether Trump would do the same should Democrats perform well come November.