The congressional primary season is underway, with hard-fought races across the United States that will help decide which candidates will be elected in November — and which party will control the House and Senate in January. While it is well-known that Republicans and Democrats have grown further apart ideologically, studies have found that many congressional primary winners and members of Congress are actually more ideologically extreme than their own primary electorates. Why?
To find out, my research looked into whether wealthy donors’ influence in primary elections has helped elect extreme congressional nominees and officials. In short, the answer is yes — especially among Republicans.
How I did my research
To test the influence of donors in primary elections, I looked at the ideologies of 3,600 major party House nominees and compared those with the ideologies of their primary and general electorate, and with those of partisan donors in their district from 2002 through 2010.
To measure the ideology of House candidates and donors, I turned to the Database on Ideology, Money in Politics, and Elections (DIME), which uses patterns of donations between campaign contributors and recipients to create ideological scores for both donors and candidates. These scores are based on the assumption that donors prefer giving money to candidates similar to them ideologically. Scores for individual donors are based on whom they contribute to, while candidate scores are based on who donates to them.
States are closing polling places. That hurts democracy.
To measure partisan donors, I take the average ideology of all individuals in the district who donated to Democratic presidential candidates and all that donated to Republican presidential candidates between 2002 and 2010. On average, there are more than 2,300 Democratic and 1,000 Republican presidential donors per district.
But what about the districts themselves? For their ideology, I turned to the 2006, 2008, and 2010 Cooperative Congressional Election Study (CCES), which asked over 120,000 constituents nationwide about their ideology and partisanship, noting their locations. To find the ideology of each district’s general electorate, I averaged the self-reported ideology of all respondents in that district on a 7-point scale ranging from Very Liberal (1) to Very Conservative (7).
To measure the ideology of each district’s Republican and Democratic primary electorate, I averaged the ideology of all Republican and all Democratic respondents in the district. On average, there were over 250 respondents, including 110 Democrats and 100 Republicans per district.
I place these different measures onto the same ideological scale using a 2010 survey that asked experts in 155 districts to place major party House nominees in that year’s midterm elections on the same 7-point scale as the CCES. There are 295 nominees with ideological scores in both the DIME and the expert survey. I use the statistical relationship between these two measures to convert DIME scores for nominees and donors to the 7-point scale of the CCES.
By the end of this, I had comparable ideological measurements for Republican and Democratic House primary winners from 2002 to 2010; for partisan donors in their district; for district residents who identify with each major party; and for district residents eligible to vote in that year’s general election for all congressional districts.
More extreme donors mean more extreme candidates win
Districts with more extreme donors have more extreme congressional nominees — even if the district’s primary and general electorate don’t share those views. When a district’s donors are one point more ideologically extreme than another district’s on the 7-point scale, its incumbent is, on average, 1.12 points more ideologically extreme as well; its primary challengers are 1.29 points more extreme; and its open seat nominees are 1.56 points more extreme. In that first scenario, for instance, the more extreme donors would replace a Democratic incumbent more liberal than 25 percent of fellow Democratic incumbents with one more liberal than 90 percent of elected Democrats — even if the ideologies of the two districts’ primary and general electorate were the same.
This varies by party. Republican nominees’ ideologies appear to correspond only with those of their donors, not with either their primary constituency or their district at large. In contrast, Democratic nominees’ ideology are also linked to those of their district’s primary electorate. If a district’s rank-and-file Democrats are one point more ideologically extreme than a comparable district, that’s associated with a Democratic incumbent who is .68 points more extreme; challengers who are .54 points more extreme; and candidates for open seats who are .97 points more extreme. If the district’s donors were one point more extreme, the district would replace a Democratic incumbent who is more liberal than 25 percent of fellow Democratic incumbents with one more liberal than 70 percent of Democrats.
The ideology of Democratic incumbents is also linked to the ideology of their district. When a district is more liberal (or more conservative), its incumbent tends to take more liberal (or more conservative) positions. The effect is statistically significant but quite small: A one-point increase in a district’s ideological positions is associated with a .12-point increase in a Democratic incumbent’s ideological positions.
Industries that donated to governors’ campaigns were more likely to be declared ‘essential’
All that changes a bit in a highly competitive race
When a district favors the Democratic Party, Democratic incumbents’ positions are strongly related to those of Democratic donors. But when districts are more competitive, Democratic incumbents are less linked to donors’ ideologies — which may suggest that Democratic donors are willing to invest in more viable general election candidates.
There’s no such variation for Republicans. Republican donors appear unwilling to back more moderate candidates who might be more viable in the general election. No matter how Republican or how competitive a district is, Republican nominees’ ideologies are strongly related to those of Republican donors.
The money vote
In short, Americans who donate to candidates use their funds to affect who runs and who wins. Democratic and Republican House nominees appear to respond inordinately to partisan donors, a group that is disproportionately wealthy and often holds extreme policy views. This may lead incumbents to champion policies more extreme than their voters would prefer — and that may favor the wealthy.
Expect donors to have an outsize influence on who wins the 2022 congressional primaries. They back candidates whose ideologies match theirs, and that helps candidates secure the resources needed to campaign successfully. Donor influence may result in a 118th Congress that is more ideologically extreme than their districts and their own primary voters.
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Jordan Kujala (@JordanKujala) is an adjunct assistant professor at the University of California Center Sacramento.