The education system in the US is screwed beyond oblivion, that's why this is happening.
And it's not just the US. I live in the Balkans and things are... well, very bad to be honest. We have the lowest average IQ in Europe.
The problem is, stupid people benefit both sides, left and right. They're easy to control, as voters. No one wants voters which can think critically.
Democracy is flawed IMO. There is no fixing this. People do rule, but at what cost. There are alternatives, but, let's face it, none of that will be implemented, at least not in our lifetimes.
A better education will, at least partially, solve the problem... in the long run, of course... but the long run is like 20, 30 years from now. Things might get a lot worse by then and beyond fixing.
Things perpetuate and there is no fixing this. The real issue is capitalism and money. You can't have an incentive to care about the people and how they are raised and educated if the only true incentive in this system is money. There is money in education, of course, but there is so much more from taking advantage of stupid people, regardless who does it (big tech, politicians, fast food chains...).