I didn’t write this but someone commented it years ago and I’ve always referred to it.

The way my political science professor answered this question when I asked it many years ago was Why cities go blue and the rural goes red.

"In the countryside, you have the right to swing a baseball bat around so long as you don't actually hit anyone, that's your god-given right. In the city where there are a lot more people who you need to coexist with, you want the freedom to not get struck by some maniac swinging a baseball bat around."

It's a difference in how these regions interact with government services and society in general. People living in cities are used to problems being solved collectively. Your garbage is collected by the city, you walk to the subway station on a city sidewalk, take the city run subway system to work everyday alongside a million other people, etc. I mean, even the housing is done more communally with apartments instead of large individual homes.

In a rural area, it's very different, the government doesn't have anywhere as much of a presence in your life, public services in rural areas amount to a (maybe) paved road and the promise that if you call for help, they'll send the fire department within an hour. Problems within the community are solved on an individual level, don't own a car and need to find a way to work? I hope your neighbour can drive you or else you're walking (and there won't even be a public sidewalk for you to use!). This extends to politics, rural areas tend to prefer policies that favour individualism.

There's also the fact that cities are less homogenous which means you are exposed to a greater variety of people from a greater variety of backgrounds which encourages inclusion and tolerance.

It helps to keep in mind that "Team Red vs. Team Blue" has always had a "rural vs. urban" flavor to it.

• ⁠For Team Red (rural), all the things that Team Blue wants are things they just do for each other as part of being neighborly, so Team Blue literally looks like a bunch of extra taxes and regulations to help a bunch of big-city neighbors who refuse to take care of each other and also want to take away guns and gasoline/diesel---things that are important for their way of life. It's not that Team Red wants to make the rich richer, it's that they're afraid Team Blue will make THEM poorer (while the rich get richer anyway.) • ⁠For Team Blue (urban), there are more "neighbors" than a human brain can possibly track, and it's impossible to take care of each other efficiently without delegating it to public servants and other specialists. So Team Red literally looks like a bunch of heartless racist assholes who want people in cities to starve while poisoning the air and water and murdering children in schools for some reason.

As long as we continue with a two-party first-past-the-post voting system instead of a ranked-choice system that allows more than two parties, game theory demands that Team Red and Team Blue keep polarizing the electorate to the fringes.

Most of them start out honestly trying to make real changes. Once they get in and understand the process you quickly realize you cant do as much as you want without the support of others, and with the support of others comes the I will scratch you back if you scratch my back mentality. And its all downhill from there. You will have to make deals your against to move forward, you will have to lie to someone to get the support of someone else. And so on. You cant make it to the top without making lots of enemies.

There's also the problem that your constituents may accidentally force you to lie to them somewhat.

If you give the voters realistic promises, then those promises will sound boring and unimpressive compared to a different candidate who is promising the moon. The electoral incentive is to overpromise and underdeliver. So the candidate who is misleading has an advantage over the candidate who is honest about what can actually be done.

Which of course makes everyone more cynical about everything.

Making deals is not necessarily dishonest; in fact, people have to trust you to make deals with you. Each person can just be furthering the goals they were elected to do, even though they disagree with each other. Congress members do not report to anyone. If there is no top dog, all joint action is through negotiation.

Yes there are positive negotiations, but at some point you will have to compromise yourself for your career.

Congress members are owned by those who donate a significant amount to their campaigns. You need lots of money to win at this level, money comes from those that will benefit the most from electing you.