Just for the sake of pretty silly argument, keep in mind a rather big chunk of the U.S. military assets are in California.
The illegals (which they would swiftly legalize) would provide all the grunts they could possibly need, and more.
Good point, but how long do you think the reconquistadores would put up with taking orders from Grand Field Marshall Michael Moore and President Barbara Boxer? They'd declare the place the new Mexican province of California Norte in short order, after a quick coup d'etat. (my apoplogies for the French term!)