Stop trying to introduce logic to the discussion. As Glenn Beck so often says, you can't discuss things logically with a liberal because their justifications for their views are so twisted, if you actually draw them to the logical conclusions they don't meet up. The circle doesn't close. There's no coherence.
So, to a liberal the pregnant Mexican woman is only here because her husband dragged her across the border. He came because he was forced by "big farming" (Bush's buddies, all) to come to do work that "Americans won't do." See, doesn't that make more sense?
As the late Steve Allen used to say, "You can't argue with that logic."