Re-districting (II)

This is such an important subject that I'm going to talk about it again. What I want to quibble with today is the idea that Democrats have a hopeless task in gaining a majority because gerrymandering has reduced the number of swing districts. The theory goes like this: Democratic representatives are all in strongly liberal seats, and Republicans are all in very conservative seats. The 2 parties have embraced a risk-minimization or incumbent-protection strategy to shrink the number of competitive districts, meaning that there are now very few seats that will ever flip, no matter national tides. Charlie Cook says there are now only about three dozen competitive races this year, with each party controlling half. This means that the Democrats would have to "run the table", win every toss-up seat, to gain a majority. So the odds are very low.

This analysis is correct as far as it goes. It is true that the number of competitive races has declined, and it is also true that the parties have deliberately reduced the number of marginal seats. The assumption is that the one is causing the other, which might not be true.

We need to look carefully at how we define "competitive races." People usually use the vote percentage for incumbents. A competitive race is one in which the incumbent receives 55% or less of the vote. And a graph of the number shows that the number of such races has declined steadily in the postwar period. But this way of defining marginality cannot disentangle the effects of incumbency from gerrymandering. A better measure is to look at the Presidential vote in each district. And here, there has been some decline (from 150 to 100 marginal seats), but there remain 100 districts that could go either way! That's a lot more than 36, abd that there are a lot of incumbents who are potentially vulnerable.

My only point here is that while re-districting has been a contributing factor to declining competition, the advantages of incumbency and big money have also influenced declining competition. There are still plenty of opportunities for Democrats to win seats. And a majority.