Why do many political issues seem to divide along urban and rural lines?
Does the urban and rural generalized mindset highlight an innate desire for complexity and simplicity, respectively?
Does degree of socialization or interpersonal trust play a role?
Could the urban vs rural divide be a manifestation of collectivist and individualist leanings a la East vs West?
Does urbanity shield from harsh realities (fragility of food production, for example) that make ruralites more risk averse?
Having lived in different remote rural areas and large cities, maybe I can give some insight.
That typical western scene where a guy walks into a saloon and everyone turns around to stare at him is actually real. It happened to me a couple of weeks after I moved to a new village and walked into the bar for the first time. The reason I mention it is because I think it plays a massive part in politics. These smaller tight-knit communities are reluctant to any sort of change. It is viewed as being a very negative thing, whatever the thing may be. Why else would there be a small gathering of people in the middle of fucking nowhere when they could be living in a city a couple of hours away?
Cities are full of young people. The youngest demographic in any population is always going to be the most progressive. It is the main reason that the urban/rural split exists, I think. Another part of the split has to do with income. For example, a big reason people are against immigration is because they are scared of an influx of people who will take all the low skilled jobs. The funny part is those immigrants are not going to end up in the middle of nowhere, they're going to end up in a city, or a large town. The jobs they are going to end up taking are the jobs available for young people in college or university - the people who are more likely to want to let them into the country. In the UK, we actually have a lot of requirements for an immigrant who wants to live and work here. A lot of them are skilled workers, or at least have some savings, because it is difficult to get into the country if they don't. Unless they are classed as refugees, that is.
Trump was voted in by people living in rural areas who feel disenfranchised. Something similar happened with the Brexit vote.
I have thought about this similarity for a while now. The difference is, in the US, it is a permanent split. The political landscape seems like it is focused in some ways around this split. Your election process is set up in a way that highlights it, and has probably even fueled some of it in a way. A Democrat running for President isn't going to give a shit about Texas, for example, because they are never going to win there. Is it Texas that creates this issue for the Democrat, or is it the Democrat that creates the issue for Texas? It's a neverending cycle.
In the UK, it is a product of the time. People do not like the Conservative government, nor do they like any potential government that could form in their place. This has been going on for so long, they do not see a Conservative government at all, just "the government", as though it is a thing that never changes no matter what it is comprised of or what it promises. That is why we voted to leave the EU, not because we wanted to, but because people just wanted to say "fuck you" in any way that they could. I suspect that is why the 18-25 bracket voted something like 70/30 to remain, because they are not yet a part of that demographic that feel disenfranchised.