In my opinion these types of problems always boil down to fear. When a person or people are afraid they act erratically. At a large scale it often leads to the wrong type of leader stepping up to use that fear for their own gain, in many cases they pull the majority together by pointing at a smaller group and claiming they're the cause of all the problems.
The only reliable solution I know to that is for people to be principled. People need to know what core fundamentals matter to them and they need to stick to those guns consistently.
Today it seems like we've lost that almost entirely. Most people hold strong views on certain topics or policies but they aren't driven by principles, that becomes clear when their strong opinions contradict themselves at a pretty fundamental level.
There are plenty of symptoms of the problem and I'm oversimplifying here, but if I could wave a magic wand and change one thing it would be to restore principles back in the average person. I honestly don't care what their principles are, I don't think that's the point, we simply can't move in a good direction without people knowing what matters to them.
The only reliable solution I know to that is for people to be principled.
...and educated.
Today it seems like we've lost that almost entirely.
We replaced it by egoism. Through decades of neoliberalism we are taught to only care about ourselves, not our communities. Making money and buying things became our main philosophy. It does not matter if you are actually well-off, everyone is in a race with everyone else.
As a result, we don't stand up against injustice as long as it does not affect us much. And the egoism makes everything seem like a zero-sum game, if an immigrant gets a house paid by taxes, then I must be losing something.
This is also what permeates current US policy - you can only win if someone else loses. In this mindset it is not possible to have cooperation that is mutually beneficial.
I hope we can heal as mankind and take care of each other again.
You stopped too soon in your analysis. Why is there so much fear? Why is there more than, say, the 1980s? The 1970s? (Or was there this much fear then, too, and we just don't remember it that way?)
Is it basically economic? We had this amazing economic ride from 1945 through the early 1970s, and that gave a view of what life could be like that permeated society and gave hope, and the hope continued long past the growth. Now people are realizing that the hope is not likely to happen to them. Is the fear caused by realizing that the hope is in danger? (That hope is in danger in another way, too. People are realizing that, even if they get better economic circumstances, past a certain point prosperity is still kind of empty.)
Or is the fear manufactured? Is it part of the propaganda? Are we being made to feel afraid, so that we can have a crisis of democracy? So that more non-democratic leaders can take over?
Or is it something else?