Shutdown non-puzzle

In an earlier post, I considered the "puzzle" of the government shutdown through the lens of the median voter theorem. Three are two (at least) possible was to reconcile this:

1. The median voter theorem does not apply.
2. The focused single issue special interest lobby. This is usually used to respond to why protectionism legislation always passes even though (possible) lower prices from free trade benefits the wider population.
3. Update: John Boehner is trying to protect his job as House Speaker