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Exploring How Legislators Navigate the ‘Primary Premium’

Prioritizing primary voters over general election voters may pay off, but can increase polarization

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If legislators have incentives to be more responsive to the primary electorate than the general electorate, it means that they're being responsive to the preferences of the few at the expense of the many.”

Laurel Harbridge-Yong
IPR political scientist

voting booth

The 2024 primary election cycle will kick off in less than a year, determining which candidates will end up on ballots in the November general election. But appealing to primary voters and their policy preferences could alienate voters in the general election when the two conflict. So what should legislators do when their primary electorate disagrees with the general electorate? 

New research shows that legislators have incentives to align with primary voters. These incentives, a product of the American two-stage election process, can shape which constituents’ policy preferences are represented in Congress—and may also contribute to polarization.

“There are going to be instances where the primary and the general electorate want different things, and we were trying to think through, ‘What are legislators’ incentives in those cases?’ ” explained IPR political scientist Laurel Harbridge-Yong, who co-authored the study with Sarah Anderson of the University of California Santa Barbara and Daniel Butler of Washington University in St. Louis.

She says primary voters—a legislator’s base—and general election voters made up of a broader constituency may have different policy preferences. Harbridge-Yong and her co-authors argue that there are two reasons that legislators might find it electorally useful to align with the primary electorate. First, primary voters are often more unified in their beliefs, so legislators will benefit more from siding with them over the general electorate. Second,  primary voters are more likely to care about whether their representative votes in alignment with their own policy preferences, a concept the researchers call the ‘primary premium.’

While this may explain why legislators see an advantage in responding to the desires of primary voters over general election voters, Harbridge-Yong says this behavior can be problematic.

“If legislators have incentives to be more responsive to the primary electorate than the general electorate, it means that they're being responsive to the preferences of the few at the expense of the many,” Harbridge-Yong said.

To understand legislators’ incentives to respond to different voters, she and her colleagues analyzed public opinion data from the 2016 Cooperative Election Study looking at the policy positions of over 64,000 Americans who voted in either the primary or general election. They discover that when the primary and general electorates were on opposite sides of an issue, the primary electorate was more unified in 73% of the cases. 

In the survey experiment looking at how 13,000 respondents evaluated hypothetical incumbents and their challengers, they find that when incumbents aligned with voters on three policy issues, the incumbent’s vote share increased. However, this effect was substantially larger in the context of a primary election than a general election.

“People voting in the context of a primary are significantly more responsive to issue alignment than people participating in general elections, and it makes sense because party is not on the ballot,” Harbridge-Yong said. “But in a primary election, where it's a competition between people in the same party, issue positions are going to matter more.”

She explains that we can see this play out now in recent fights around the debt ceiling or other issues that have broad public support. In these situations, some legislators seem more worried about what their base thinks versus the general electorate.

“To the extent that primary voters, who are the stronger partisans and more committed ideologues, hold more extreme positions, they may pull legislators away from being able to take moderate positions or compromising positions, and they will instead fight to the bitter end and stick with what the primary electorate wants them to do,” she said. “And that can increase both polarization as well as gridlock.”

How can we reform the election process to address the primary premium? Encouraging more people to vote in primary elections could help change the composition of voters, bringing in more moderates and making primary elections look more like general elections. 

Harbridge-Yong also says shifting primary elections to non-partisan elections might help increase participation of moderate voters. In these primary elections, voters could vote across party lines on the ballot, potentially picking more moderate candidates from both political parties. Her recent research looking at the new top-four primary in Alaska suggests that this type of election could increase moderate candidates’ chances of winning. 

“There's some logic to suggest that there are more opportunities for moderates to feel like they have the kind of choices that match what they want to express in those types of primary elections,” she said.

Laurel Harbridge-Yong is associate professor of political science and an IPR fellow.  

Photo credit: iStock

Published: June 22, 2023.