We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
That passage by itself in our collective unconscious is an advocation of equality, it makes it so that we don't believe in superiors and inferiors. We hold all people all citizens to be equal. So we can't really have certain people be put down, even if that might be necessary to tame the pride of the migrants who come here.
For instance our culture would balk at doing things like requiring all migrants to kowtow to any passing native born citizen or things like that. Now I know you might be thinking such a thing is merely to sooth the ego of the locals so they can pretend to be superior. And sometimes it is that, and it's useless. But other times it proves handy to control a rebellious new group of people in your nation.