Bouncing ideas around in the comment section made me realize what really bugged me about the article on voting, and it comes back to the brilliance of Vernon Smith (who, of course, stood on the shoulders of other giants).
Marginalism is fine. It's an important way of thinking about human behavior. Don't dump it.
But - what bothered me is that the narrow marginalist argument being made seemed in dire need of a consideration of the difference between ecological and constructivist rationality. Evolved norms around voting have an ecological rationality even if they don't always pass the test of a constructivist rationality that is posed in a particular way (specifically - if you pose it in terms that economists usually use, voting could easily fail the constructivist rationality test).
His classic article on it is here.
I have a busy week, but I ought to re-read this again soon.