God has no borders, and even if he did, I'm not convinced that we would be better off without the "illegals". Sure, they're breaking the law, but I don't see how them coming here hurts us. The depressed wage argument is weak when one looks at how fast U.S. per capita incomes have grown in the past five years...
Now, if we decide to give them all welfare, that's a different matter, but whether or not we extend services to them is our decision, not theirs. Don't blame them for the welfare that we give them. They're not responsible for that policy.
Deuteronomy 32:8 says that, "When the Most High gave the nations their inheritance, when He separated the sons of man, He set the boundaries of the peoples." Acts 17:26 says that God sets "bounds of habitation" among every nation of mankind, that they should seek God.