The ‘Rat is using semantics. I agree, because a true IMMIGRANT is here LEGALLY. Anyone who is in the Country by any other means, or lacking proper documentation, has no RIGHT to be here or stay here. Our law should reciprocate Mexico’s. Check it out.
The word has no connotations of legal status. If someone moves to a country he is a migrant, an emigrant from his old country and an immigrant into his new country. If he does it legally this migrational aspirations will be fulfilled. If he sneaks across borders illegally and is caught then he will be an involuntary emigrant. "Illegal immigrant" is a clunky phrase. I prefer "wetback," a word with a long and honorable history.