Redistricting and polarization: who draws the lines in California? by Corbett A. Grainger

In the United States, the process of drawing election districts is left to individual states, and critics of legislative redistricting often argue for independent panels to take control of the process. A common claim is that legislative redistricting has been a major contributor to polarization in the American political system. Previous attempts to test for a relationship between redistricting and polarization have generally relied on cross-state comparisons of redistricting methods and examinations of behavior in the House of Representatives. In this paper, I exploit the alternation between legislatively drawn and panel-drawn districts in California since the mid-1960s. Using data at the state legislature level, I find evidence that legislatively drawn districts have been, on average, less competitive than panel-drawn districts. Moreover, as districts become “safer,” legislators tend to take more extreme voting positions. Finally, I find evidence that legislative redistricting (compared with panel-drawn redistricting) is associated with increased polarization