The USA was founded on Classical Liberalism.
And yes, at the time, it was RADICAL!
(Not that you'd know it today from the right wingers speechifying.
The Us vs Them ideologies are always going to be with us too, I'm afraid. It's human nature. Take a 3-6 month old child who gets to screaming when they see an unfamiliar face -- not mom or dad, that is. Fear of the "other" I believe is an internal, instinctual, maybe genetic, protection factor of humans.
But, education can liberate us from that.
And help us tolerate and celebrate diversity.
Just my two cents, for whatever its worth.
Shalom!