This assumes, though, that people don't read more when they're given a slate and that the puppy list does not overlap the books these people would otherwise have read. That said, I have to admit that neither of these are entirely likely and the slate probably did influence voting inordinately.

I think, though, that rather than randomness, a small group is voting their party ticket in a primary. The appearance of the Williamson thing on the final ballot is a tell; if anyone was reading critically, that wouldn't be there.