Partisan Traps

The desire to stifle political competition may lead elected officials to eschew common-interest reforms and focus instead on zero-sum partisan conflict. By forgoing opportunities for common-interest reforms, incumbents may convince their constituents that such reforms are rarely feasible, so that policymaking is primarily about choosing partisan sides. Voters with such beliefs vote based on ideological alignment, rather than factors such as competence or honesty. This is electorally beneficial for incumbents, who are typically ideologically aligned with their constituents. We capture this logic in an infinite horizon model and characterize the resulting dynamics of politics and policymaking. Equilibrium exhibits partisan traps-voters are pessimistic about common-interest opportunities, and hence elect ideologically aligned incumbents, and incumbents respond by behaving in a purely partisan manner that shuts down voter learning. Partisan traps often occur in equilibrium even when common-interest reforms are in fact frequently feasible. The model shows how elite and mass polarization are intertwined, with politicians engaging in strategically polarized and polarizing behavior which leads to pessimistic beliefs among voters, who then vote in partisan fashion.