Women are running for office in record numbers this year. Most of those running are Democrats. While women comprise 43 percent of Democratic candidates in 2018 congressional general elections, they make up only 22 percent of Republican Senate candidates and only 13 percent of Republican House candidates. While Democratic women won House primaries at rates 20 percentage points higher than Democratic men, Republican women and men won House primaries at similar rates. Currently, 73 percent of the women in serving in Congress are Democrats.

While 2018 may be a record-breaking year for women candidates in many ways, the midterm elections are unlikely to significantly alter the longstanding party gap among women officeholders.

What accounts for the massive party gap in women’s representation as candidates and officeholders? Why do so few Republican women run for and win elected office? In a new paper, we reveal how differences between the Democratic and Republican party cultures lead Democratic elites to support women candidates more frequently — and because of their gender — while Republican elites do not. This distinction lays the groundwork for substantial differences in women’s emergence and success as candidates in the two parties.

We identified the cultures shaping the behavior of Republican and Democratic elites using a 2014 survey of donors to congressional party campaign committees and liberal and conservative women’s PACs. Donors are part of the extended party networks whose support influences which candidates are recruited, choose to run, and are able to win office. Consequently, their attitudes about women candidates can substantially shape how often women run and win in each party.

To what extent do Republican and Democratic party elites support women candidates? Our research reveals that “women’s representation policy demanders” — groups that advocate for greater support of women candidates — exist in both parties. However, gender plays a much larger role in the political activity of Democratic than Republican donors.

Democratic donors are more likely than Republican donors to report they were motivated to political action by a candidate’s sex or gender, are more likely to identify gender issues as important to their decisions to support a candidate, and are more likely to use gender-related groups to find candidates to support. These findings hold regardless of the group to which donors contributed funds.

A closer look at our results highlights several key takeaways:

Democratic elites are motivated to political action by candidate gender; Republican elites are not. Specifically, among Democrats, even mainstream party donors often support candidates due to gender-related concerns, while even Republican donors who donated to women’s PACs infrequently reference gender as a primary motivation.

For example, while 59 percent of Democratic Party donors indicated gender issues are a very important component of donation decisions, only 16 percent of Republican women’s PAC donors said the same. While 80 percent of Democratic donors to women’s PACs noted a gender-related organization among the groups that helped them decide on candidates to support, only 46 percent of Republican women’s PAC donors did.

This distinction helps explain why Republican women are disadvantaged in fundraising compared to similar Republican men, while Democratic women in some cases raise more than their male counterparts.

Liberal women’s PACs are woven into the fabric of the Democratic Party while conservative women’s PACs are not similarly integrated into the Republican Party

Women’s PACs are actively supported by Democratic elites, and virtually invisible to Republican elites. Among Republican Party donors, an average of 72 percent report they have “never heard of” the five conservative women’s PACs we asked them about, while only 7 percent of Democratic party donors say the same about liberal women’s PACs. On the other hand, an average of 36 percent of Democratic Party donors and 65% of Democratic women’s PAC donors report actively supporting the liberal women’s PACs noted in our survey, while almost none (2 percent) of Republican Party donors and only 17 percent of conservative women’s PAC donors, on average, report supporting the conservative women’s PACs we asked about.

In other words, liberal women’s PACs are woven into the fabric of the Democratic Party while conservative women’s PACs are not similarly integrated into the Republican Party.

The effects of this distinction can be clearly seen in scholarly research highlighting that Democratic men are more likely to donate to candidates who are endorsed by the premier liberal women’s PAC, Emily’s List, and that liberal women’s PACs are able to fund candidates at substantially higher rates than conservative women’s PACs.

Its effects are also evident in the fact that two of the conservative women’s PACs we examined (She PAC and Wish List) have folded since our study, and candidates endorsed by conservative women’s PAC Susan B. Anthony List had very low win rates in 2018 Republican primaries. In contrast, Democrats this year are funding women candidates through women’s “giving circles,” are supporting slates of Democratic women through crowdfunding, and have launched a new women’s PAC — Elect Democratic Women — focused on raising funds to support women Democrats in this election and beyond.

The parties’ divergent support of women candidates can be explained by distinct cultures within the two parties. We argue that the groups that have gained power within the Republican and Democratic parties over many decades have constructed different cultures regarding gender roles. The Democratic Party culture has been shaped by prominent groups in the party that have demanded policies aimed at expanding rights and representation of specific identity groups within the party — including the civil rights movement and the women’s rights movement — and created a culture supportive of women’s representation and activity outside traditional gender roles.

In contrast, the social and religious conservative policy demanders that gained prominence in the Republican Party defined a party culture that enforces traditional gender roles.

Party cultures are so powerful, they affect the behavior of Democratic and Republican elites regardless of their personal attitudes toward gender roles. Democratic donors are more motivated than Republican donors to take political action on the basis of candidate gender, even when we control for — or essentially equalize members of each party by — their identification as evangelical, support for traditional or progressive gender roles, and other traits like gender, race, age, and ideology.

This leads us to conclude that as long as the party cultures we identify persist, even Republicans with progressive gender attitudes will encourage and support candidates in ways that maintain traditional gender roles, and even Democrats who are not personally very concerned about women’s representation will seek out and support women candidates in order to meet the demands of the groups prominent in their party that have actively shaped their party’s culture.

Democratic women are prominent on the campaign trail this year in a way Republican women are not. Democratic women also talk about their identity in very different ways from women seeking office as Republicans. Our research suggests the different cultures among Democratic and Republican party elites lay the foundation for these patterns and give Democratic women an advantage when it comes to seeking support from members of their party when running for office. Given this, it is perhaps unsurprising that even a record-breaking year for women is set to only reinforce the persistent party gap in women’s representation.

Melody Crowder-Meyer is an assistant professor of political science at Davidson College. Rosalyn Cooperman is an associate professor of political science at the University of Mary Washington.