It's a great call - I'll post a follow-up with that detail and try to find a couple other examples from people in other geographies and demographics. My take (from this exercise and looking at ProPublica's data) is that behavior varies significantly based on both WHO campaigns think you are and WHAT you've done lately (what you've read, which sites you've visited, have you donated or volunteered, etc).

This complexity is going to make analysis nearly impossible in the future as political (and marketing) messaging becomes incredibly personalized.

(I'm actually author and OP here is my also-HN reading brother who beat me to the punch)