there shouldn't be a "closing of the gates". a very likely outcome would be the drop in remitences that equate into the millions. what then would happen to their economy? what then would happen to the relation of the U.S. and Mexico? the greater the gap in economies the more likely a severe form anarchy, there should be another way.
Germany's Merkel says military efforts needed in Syria but they won't end war (Reuters)
from the article: A flood of Mexicans