California's redistricting process of 2011-2012, conducted by the California Citizens Redistricting Commission, has been held up by many as a redistricting ideal. It is easy to see why. In a redistricting cycle that was largely dominated by partisan lawmakers, self-interested incumbents, and protracted legal battles, California's redistricting stood out as one of the few truly nonpartisan, independent processes. The success of Proposition 20, the ballot initiative that was approved by 61% of voters in 2010 and established the Citizens Redistricting Commission, gave hope to reformers around the country that there is a way out of the cycle of endless gerrymandering.

Some of the goals of Proposition 20 were achieved: California's congressional elections have much more democratic legitimacy using district lines drawn for the interests of voters, not politicians. But to the extent that reformers expected the Commission to create more competitive districts and lead to more accountable legislators, California's new redistricting model has been unsuccessful. Recent claims that "California now has some of the most competitive districts in the country" or that if other states adopted similar commissions "more House members would come from politically diverse districts" are largely exaggerations.

California did see an unusually high degree of incumbency turnover in 2012, at least for notoriously entrenched California incumbents. Five incumbents were defeated in the 2012 general election, and an additional nine decided not to run. 26% of California's current delegation is newly-elected, slightly higher than the national rate of 19%. But the level of incumbent defeats in 2012 is deceptive. The Commission did make major changes to many district lines, drawing incumbents out of their old districts and setting up a series of incumbent-on-incumbent races. Such races are a one-time-per-census event, however; now that the dust of redistricting has settled, there are very few districts that could realistically be competitive in 2014 or, for that matter, in any election before 2022.

An analysis of the underlying partisan nature of California's districts before and after redistricting, as shown in FairVote's new factsheet, reveals that the overall competitiveness of the state's map has not increased. In fact, there were exactly as many competitive districts (that is, districts that voted within 3% of the presidential candidates' national margins) in 2012 as there were in 2008: 5. There were also just as many safe districts (which voted at least 10% more for one candidate than did the nation as a whole) in both elections.

The chart below demonstrates this remarkable consistency in districts that FairVote categorizes as "swing," "lean," and "safe," before and after nonpartisan redistricting.

The graph seems to suggest that the Citizens Redistricting Commission had no effect on district competitiveness whatsoever, but there is one variable that it does not control for: shifting voter preferences. Because it looks at pre-redistricting districts through the lens of the 2008 election and post-redistricting districts through the lens of 2012, it does not account for any changes in the partisan composition of districts between the two elections.

A second graph below addresses this issue by showing how competitive the post-redistricting districts appeared using 2008 numbers. Interestingly, at the time that the Citizens Redistricting Commission drew its new map in 2011, it may have seemed that it was slightly but noticeably increasing the number of competitive districts and decreasing the number of safe ones, based on 2008 presidential election data.

By the time the new districts were actually put into use in 2012, however, the nationwide trend toward more polarized districts had completely cancelled out the new map's increased competitiveness. This data backs up Bill Bishop's famous "Big Sort" theory: regardless of how California is divvied up into districts, voters are increasingly clustered around other voters with similar partisan preferences.

As we discussed in greater detail in a post earlier this year, the California case is illustrative of both the benefits and limitations of independent redistricting commissions. California's citizens have taken away from the politicians the power to choose their voters, and that was reflected in the high incumbent turnover in 2012. But no matter who is drawing the lines, the polarization of the American electorate makes achieving competitive single-member districts effectively impossible on a large scale.

California's Top Two primary system creates an additional opportunity for competitive elections by introducing the possibility of intraparty races. A significant increase in competition as a direct result of Top Two is unlikely, however; only two incumbents lost intraparty races to a challenger in 2012, and those events may become even rarer as incumbents accrue incumbency advantages in their new districts.

Only through exploring the use of multi-member districts elected by fair representation voting systems can independent commissions like California's be empowered to draw maps that give all voters a say in their representation and hold all elected officials accountable.