Don't misunderstand, the people moving to the US are blameless. Imperialism works by siphoning up all of the skilled labor around the world for itself in order to make life better for people within the imperial core, and this is part of how the imperial nations underdevelop other countries. People get educations in their home countries (often at the government's expense) and then they take that education out of the country to put it to use in the US (or France or Canada etc). They're just going where the jobs are, though, that's not their fault at all.