What he's trying to do with Mexico in propping it up is a separate issue that conservatives oppose as well. Could be he's attempting to kill two birds with one stone, both of which are bound to fail.
I'm for upping immigration quotas to help feed worker demand. Not just flinging open the border and allowing them full access to welfare/medicare/social security. Also, people willing to INVADE us in a criminal enterprise are NOT the kind of people we want coming here. Period.