How do we know that higher turnout benefits Democrats?

Preliminary thoughts on a new book that claims it doesn’t

On Twitter this week Matt Grossman linked to a new book called “The Turnout Myth” in which the authors political scientists Daron Shaw (a former professor of mine) and John Petrocik suggest that the usual claim that higher turnout benefits Democrats is wrong. Grossman tweeted out the following graph as a central finding of the book. In congressional elections with higher turnout, it shows, Democrats have not tended to out-perform other elections with lower turnout.

Case closed? I’m not entirely convinced, and actually have a few pretty severe issues with this analysis. (Note that I have yet to read the book, so this criticism does come with slight ignorance attached. The authors may very well address these criticisms. I’ll address them again after I’ve read it. But my hope is that this just gets out analytic juices flowing.)

First, I think that basing the claim on the historical relationship between Democratic vote and turnout nationally might be conflating too many other variables. The…