The median voter theorem states that, in a majority rule voting system, the preferences of the median voter are expected to win. One consequence of this theorem is that vote maximizing parties in a two-party system will tend to coalesce around the median voter (because the other party will eat their lunch if they move too far from the center). Boris Shor from the Harris School leverages this theory and some data on state legislator preferences to predict that the Republican that Chris Christie appoints for the late Sen. Frank Lautenberg’s seat will likely be quite moderate relative to national Republicans, as the median voter in NJ is more left-leaning than the median voter nationally:
Looking at their data, it seems the predictions about party behavior largely coheres with the expectations of the median voter theorem with one massive outlier: California. According to Shor’s calculations, the average Democratic legislator in California is more left-wing by a wide margin than the average Democratic legislator in any other state. Indeed, the average Democrat in California appears to be more extreme than the most left-wing member in Massachusetts for instance. This outcome might be justifiable under the median voter theorem (I would not be surprised if the median voter in California were the most left-leaning of all the states) if the average California Republican were not simultaneous more conservative than the average Republican of any other state.
How can one state plausibly contain both the left-most state Democratic delegation and the right-most state Republican delegation without invalidating the median voter theorem?
Firstly, one must remember that legislators appeal to the median voter in their district, not the median voter in their state. If the partisan makeup of districts deviates wildly from that of the state (e.g. due to gerrymandering), it can lead to intense partisan differences amongst lawmakers. It does not seem that gerrymandering is to blame in this instance, as California constructs its Congressional districts using a nonpartisan citizen panel rather than a partisan system. However, these panels construct these districts to be compact and geographically sound, rather than competitive, which means they can do nothing about political segregation (leftists living by leftists and conservatives by conservatives). Indeed, one of the complaints the California Republican Party issued in 2012 against the citizen board is that it tended to make districts less competitive, not more, than the partisan process largely due to the amount of political segregation that exists in California. Thus, even non-gerrymandered districts could be pushing California towards extremism, though likely not to the levels that Shor observes.
Another plausible hypothesis is that the California Republican Party has priorities other than vote maximization. Remember that one of the conditions of the expectation that parties would converge on the median voter is that they do so with the intention to win the majority of the votes. Perhaps the California Republicans, dispirited by how far they would have to compromise their principles to appeal to the median voter in California, have given up entirely on the prospect of winning a majority in the California legislature. They instead could have consolidated their support in the most right-leaning districts and adapted the posture of a permanent principled opposition party, contended to win the ~30% of the seats virtually guaranteed to them and shoot spitballs at the majority from the gallery. The lack of competition for the median voter would simultaneously free the California Democrats from any obligation to moderate their positions, leading to an outcome analogous to what Shor finds. However, if true, it means there is a huge political opportunity for a moderate Republican or a third party to truly clean house in California, as both parties have effectively abandoned vote maximizing postures. This seems to be Mark Zuckerberg’s operating assumption, and the success of his group in influencing California politics might give us an insight into how correct this explanation truly is.
Finally, there is a more systemic explanation for both parties’ behavior: they have given up on legislating rationally because state legislators themselves have lost any real power. The government of California long since given up on the ideal of representative democracy, settling major policy issues through yearly plebiscites instead. With no real consequences for their votes, legislators can freely make symbolic stands for their respective bases and funders without suffering at the ballot box. In effect, Shor could be comparing apples to oranges by using the same input (the voting records of individual legislators) across states where legislators have varying levels of power. New Jersey legislators vote to engage in policymaking (with the requisite compromises and trade-offs that entails), while California legislators vote to engage in theater, leaving the true policymaking in the hands of the governor and the public. There is some preliminary support for this hypothesis. I took Shor’s state level data and combined it with data on ballot initiatives from the National Conference of State Legislatures. Using the total number of ballot initiatives from 2008-2011* as a proxy for how strong direct democracy is in a given state, I performed a simple bivariate regression using the ballot initiative total to predict the mean difference between individual legislators in a given year and the difference between the mean legislators from both parties. For each of these four regressions (two for each the state House and Senate), the effect of direct democracy on partisan difference was sizable, positive, and significant (p < 0.001 in all cases), and explained roughly 20% of the total variation in legislature partisanship (a little less in state Senates and a little more in state Houses). Obviously, this is just one variable and there are a variety of other factors that other researchers could and should control for, but it does lend some credence to the idea that direct democracy could be pushing California legislators towards extremism.
If true, that last explanation also offers some insight for grappling with the increase in partisanship at the national level. Congressional legislative authority has been progressively delegated to the executive and the bureaucracy, including, most recently, proposals to allow the president to determine how to apportion the (already power-limiting) sequester. This could be a vicious cycle too. The more Congress debases itself with petty partisanship, the more the delegation of power to super-committees or executive agencies appears necessary, which only increases the incentive for further empty partisanship. Perhaps it might be necessary to entrust Congress with more power and resist efforts to tie them to the mast in order to break this cycle and bring sanity to the governance of the largest non-profit in the world.
*To give you sense of the distribution, the median state had 10 initiatives over these 5 years, with Delaware having 0 and California having 54.