Doug Ahler, Jack Citrin, and Gabriel Lenz conducted an experiment where people voted either using the new top-two ballot or the old closed primary ballot. Moderate candidates fared no better when people voted with the top-two ballot. Thad Kousser, Justin Phillips, and Boris Shor investigated the effect of the top-two primary on representation. They found that legislators tended to stray further from their district’s average voter under the top-two primary than before. In other words, the new California system has improved neither polarization or accountability.
Why don’t these reforms appear to work? There are a variety of reasons. Perhaps there aren’t enough true independents voting to make open primaries a means of reducing polarization. Voters may lack the necessary information or aptitude to distinguish among more moderate and more extreme candidates. Or party elites and donors may ensure that only extreme candidates end up deciding to run.