They vote for their material interests in the same sense that a man walking at night with sunglasses picks the best path. He thinks it's obvious but he really needs to take the sunglasses off and maybe get a flashlight. He's walking a stupid path and will probably fall into a ditch.
Fox News is probably the sunglasses in this metaphor.
Out-groups to bind, in-groups to protect. That's it. Often on a purely emotional level. Having the out-group be just out and about living life feels wrong to that kind of person. There has to be hierarchy, they feel.