Does this have something to do with the ethnicity of their immigrants, or does it have more to do with the fact that they're farm states? Where the inefficiency of people living so far apart from one another leads to poor infrastructure, and an uneducated populace that's easily manipulated by the worst sorts of politicians. From corporate puppets, to sociopathic power mongers, to the just plain old too stupid to win an election anywhere else. Basically anyone who can afford enough ad space.
Maybe those rural states do need some extra help, but not in the form of gerrymandered legislators - that's like trying to cure anemia with more leeches. What they might need is extra government assistance to compensate for their geographically inherent inefficiency. Particularly in education.
So of course, in such places, those in power are pushing to gut their education systems as thoroughly as possible. From their inane voucher programs and shutting down public schools, to trying to make sure that kids learn how science is just an alternative to religion. It's almost like they want to keep their constituents stupid.