David Brooks at the New York Times has a go at analysing why it seems that Republican voters seem happy to vote against their own economic interests.
He takes the "they have a residual sense of independence and dislike of government that came from the American frontier communities" line, which puts a somewhat noble sheen on the matter. Who can dislike a person who declines a government handout on the grounds that they would rather make their own way in life and fully control their own destiny?
The trouble is, as a very large number of people in comments are saying, lots of Republican voters actually want to hold onto their government benefits (in the form of Medicare, veteran's entitlements, etc) as strongly as they want the right to have an armoury in the basement. Hence, Trump support comes from his promising everything to his base - less government and more government at the same time. Also, there's no doubt that Trump played up to resentment of others - countries that have done well with globalisation, migrants (both legal and illegal, when you think about it), blacks and feminists.
I think Brooks was too generous - he should have been more critical of the urge of Republicans to vote for their emotional interests, especially when they have been conditioned and informed by the grossly misleading echo chamber of the Right wing media - which has to take an enormous amount of blame for the sad state of American politics. (He could have then spread the same criticism around to argue that for those on the Left for whom identity politics is everything might also sometimes be voting for their emotional interests. The thing is, though, someone for whom - say - gay marriage is the most important issue is at least not as likely to jeopardise generations of descendants to planet wide problems by denying science on climate change.)