Well, I can only speak for my family's experience, but some were amusingly prejudiced against 'Bohemians.'
You see, they didn't start settling in Texas until the late 1800s. I suppose we're calling them Czechs nowadays. Still don't trust em.
EDIT - Back on topic, please don't rely on a bunch of arcade enthusiasts for legal advice. No, we're not marching people out at bayonet point, but your friend shouldn't be messing around with this stuff and he shouldn't be telling anyone besides a lawyer that he's here illegally.