The Cynics were the first people to recognize that monopolitanism was a dangerous mindset which often leads to parochialism, moralism, xenophobia, narrow mindedness, etc. In its stead, they taught cosmopolitanism, or seeing yourself as belonging to the entirety of the cosmos rather than a local political and cultural structure.
In history, whenever you see societies move toward closing down in a kind of nationalism or totalitarianism, there is a critical increase in danger to the Other or alter. We can see that we are moving back toward this cycle here in the States. Expand, contract.
In the last two hundred years such contractions have not always meant the closing of borders per se. Sometimes it means closing down to what is different nearby, sinking into false nostalgia about how things were better before other people got access and alternate ideas took hold. It can even become the notion that the world would be better if it was controlled by “Us” and forced to do things “Our” way. This, of course, is how colonial power goes off the rails and how xenophobia develops into fascism.
Wanting your way of life to be the only way of life is just another variation on monopoly. Given that capitalism tends toward monopoly, we should not be surprised when we see xenophobic capitalists continually eschewing the cosmopolitan core of republican governance throughout American history. It compresses rather than compromises. It excludes rather than includes. It differentiates to discipline rather than identifies to communicate.
To call the presumptive Republican Presidential nominee a fascist of some variety is simply to use a historical label that fits.
Cosmopolitanism is not a tribal trait; it is a virtue, as much as courage or honesty or compassion. Almost without exception, the periods of human civilization that we admire as we look back have been cosmopolitan in practice; even those, like the Bronze Age, that we imagine as monolithic and traditional turn out to be shaped by trade and exchange and multiple identity.