Kendall, there are so many that is would cost more to export them than to citizenize them. Besides, many are from southern Mexico, Guatemala, El Salvador, etc., so they know the way.
For New York, apprehended aliens from Mexico accounted to only 18% of the total, so lots of others have come in from the cold, so to say.

There, I heard a teen use citizenize; I am adding it to Mudcat vocabulary without charge.

Lots of jobs that locals won't take. Near Calgary is a large slaughter and meat packing plant, the workers all Somalis except for the boss man. Don't know if they are all legal or not. Less stressful than pirating. Good workers!