Secure majorities, unequal districts: One person, one vote & state bipartisanship

In 1964, the Supreme Court ended legal state legislature malapportionment. This paper considers the effects of this federal action on the partisan and ideological behavior of state legislatures in the immediate period following the Reapportionment Revolution (1959–1974), particularly in states with vast rural and urban representational differences. Using a novel dataset of state-level malapportionment rates, legislative partisanship, and state-level ideology, we find that nation-wide requirements led many state legislatures to become more competitive. Yet, while this electoral competition encouraged immediate bipartisanship, at least measured by partisan makeup and ideology, this partisan harmony was short-lived in states that malapportioned along geographic lines before the Redistricting Revolution. Thus, while we find evidence that institutional change can decrease partisanship, in cases where partisan control is reflective of perhaps a demographic or geographic imbalance, these changes can lead to a backlash effect.