The primary premium: Why legislators are incentivized to side with primary voters over general election voters

How are legislators incentivized to behave when their primary and general electorates disagree about an issue? We argue that primary electorates are generally more unified in their issue preferences and more sensitive to roll-call positions than general electorates, incentivizing legislators to prioritize primary voters when facing conflicting demands from the two groups. Using the 2016 Cooperative Election Study and an original survey experiment with over 13,000 respondents, we show that primary voters are both more unified and more likely to adjust their vote choice based on policy alignment. When we combine electorate unity and voter sensitivity, we find that US senators had more to gain by siding with their primary electorate in 84% of the votes where they were cross-pressured. This helps explain why politicians are incentivized to cater to their primary electorate − shaping patterns of representation and policy outcomes in American politics.