Edit: Jesus, i'm just catching up on this Charlottesville sstuff... What the hell is happening?
The short answer; Globalization and the disruption across power structures that it brings. Loss of national identity, fear of being a minority in their own country, persecution complex and seeing other groups as part of a threatning whole wanting to take their stuff. They blame their worsened quality of life on minorities.
The long answer; The United States like other western nations are forged through conquests. When the whites are the overwhelming majority there is no need for them to identity and stick together. But once you see a global society with free movement of peoples, they are beginning to become a minority in a country they feel is theirs.
This give rise to white identity politics and the idea that whites are having what is rightfully theirs... snuffed from underneath them from what they see as bad people. Xenophobia, paranoia and racial, religious and ethnic stereotyping. Outlets like fox news and breitbart riles them up and more and more white people become radicalized as opportunity and quality of life dwindles. POC and minorities are blamed as being the perceived under class that takes everything away from them.
This is pretty standard stuff, and has been throughout the last 2000 years. It's par for course in other countries where the majority population falls on hard times. It's easiest to blame the minorities as they are the ones who are perceived as bringing change.
You need to remember that it's not more than a single lifetime ago- about 80 years or so, that the way we did things in the west, as taking what we wanted at the expense of other people. It's not even a lifetime ago since the European empires stopped colonizing their human abuses of people all over the world.
When the US was founded it was on total destruction. That is how nation borders everywhere are formed.
So when you get a globalized society with a mix of people from everywhere, the people who had control, are losing that control, and what you see now, is groups of white people thinking they can stop globalization and keep the united states from having white people become a minority in their own country. Fear and anxiety.
Alex Jones and other of this ilk are also funneling this line of thinking, and its one of the driving forces behind the desire to deduce the government to nothing, and also why libertarian thinking is becoming more of a thing all over the western world.
We see it in Europe too.
Even in Scandinavia, where people are becoming critical of their own welfare state as they see outsiders coming in with no desire to integrate, but take up resources without integrating or assimilating with the values of said country.
A part of that might also have something to do with that nation states, and the taxation based contribution therein is based on various forms of solidarity- The idea you want to contribute and give to your own country men.
But with a free movement of people from all over the world, some people see themselves distanced from their own country as the country becomes more globalized and diverse and fair.
Conservatives in most places are for stopping change, keeping the old ways and the way things where. traditions and structures.
Don't change things that ain't broken (for them!). That is why they bake on old glories and old nationalism. If you watch Steve Bannons movies, they all try to hammer this theme that the US is only strong and powerful when united against an enemy.
He feels a good war is needed, and that the country is dying from the underclass of poor people who are dependent on resources. He thinks that if they had a big world war and they could conscribe every adult man and woman for military service, the US would get back into shape. T
his is fantastical military perversion and a grandiose militant way of thinking extricated by the military industrial complex.
The US largest and most important export is war, and one way or the other, it benefits from conflict. Either through the militarization of civilian police, the heightened security and defense spending at home.
So much RnD and profiteering goes into defense that Trump can keep stirring the hornenes nest. The Wars if afghanistan and Iraq might have cost the taxpayers a lot of money (and iraqi and afghans, their lives), but a lot of people made a lot of money of contracting jobs of those war, and the post-9/11 militarization.
For white radicalized conservatives, this paranoia of white people being outbred in their own country is strong all over the western world. You see it in France, the UK, Italy, Scandinavia.
Incompatibility in values, religious and power structures. Your place of birth is your privilege- your ticket in life, and basically your place of birth has always dictated your level of opportunity and privilege. globalization is watching all of human history fight over borders and lands being shaken up.
500 years ago, you'd just have declared war, enslaved or killed everyone. It's the same story in every powerful country on earth.
And this feeling is so strong, that even when this line of thinking will hurt them- they are so afraid of losing everything they have, that they will almost literally commit kamikaze to stop foreigners from taking their stuff.
That's the mentality you see with trump supporters in flyover states who desperately depend on social services, health care and governance programs.