marginalized groups

Marginalizing people is what America is based on. Marginalization of slaves, Native Americans, and immigrants by white men are the oldest and most obvious of the marginalized. Once immigrants reach the second or third generation, they begin to marginalize immigrants.
Women have always been marginalized.
Homosexuals have been recently been marginalized although historically they lived on the fringe. Intellectuals are marginalized.

Marginalization is the key to political division. That's why white conservative men feel marginalized. The world is moving forward and they want to move backward, so they respond with "we will not be replaced".
So long as we marginalize, none of us are free.