Provoking the opposition

Parties in primary elections often choose between candidates who appeal to their base and those who appeal to the broader electorate. I present a model of primaries where incumbents can exploit this trade-off the opposition faces between ideological congruence and electability. In the model, incumbents reduce their appeal to the median voter by moving away from the center. In doing so, they provoke the opposition into nominating extremists, improving their reelection prospects. This mechanism generates elite polarization as politicians leapfrog voters — not despite electoral concerns, but because of them. The analysis fits the observation that incumbents sometimes move away from the center near the end of their term. Provoking the opposition relies on two conditions: divergence of primary and general electorates and a limited set of potential nominees. I argue that partisan sorting and changes in nomination procedures over the last decades made this strategy viable.