> They benefitted from it so hard they voted for the exact opposite with eyes wide open. Twice.

This conundrum, like so many others in public discourse, is downstream of the widespread but fundamentally incorrect belief in free will (which in turn is downstream of belief in supernatural powers, because free will sure as hell isn't explained by anything in nature).

Nothing is in anyone's control. There's no such thing as "eyes wide open". People's behaviors are 100% downstream of genetics and environment. Some people behave rationally some of the time, and to the extent they do so it is because the environment set them up to do that. There is absolutely no coherent reason to generalize that into the idea that most people vote (or do anything else) rationally.