UC Berkeley

To improve representation and alleviate polarization among US lawmakers, many have promoted open primaries - allowing voters to choose candidates from any party - but the evidence that this reform works is mixed. To determine whether open primaries lead voters to choose ideologically proximate candidates, we conducted a statewide experiment just before California's 2012 primaries, the first conducted under a new top-two format. We find that voters failed to distinguish moderate and extreme candidates. As a consequence, voters actually chose more ideologically distant candidates on the new ballot, and the reform failed to improve the fortunes of moderate congressional and state senate candidates.