Our borders are definitely protected, especially the southern one. We don't have reasonable immigration policies, but we do have the sort of cruel and punitive ones people who oppose immigration favor, and a vast and well funded detention and legal apparatus to support them. These are the results. Obviously, people who arent very thoughtful or curious think cruel and restrictive policies will prevent people from coming or entering the country. But when they inevitably dont, all they do is call for more cruelty and crackdowns (or magic bullets like giant walls), invoking the "crises" their favored policies created.