Notify Texas that if they would like to become the Dominionist Homeland, they are welcome to secede without being prosecuted for treason for some time period, provided that Chuck Norris is indeed made President of Texas. Then close the border and seal it with nuclear weapon-proof blast walls.
It'd be like having our very own Australia. New punishments for criminals could include "exile to Texas."
DH just added that any survivors who managed to escape back into the US could be immediately put into Army Rangers/Navy Seals type training for elite combat missions.
Realistically, I have no idea. Being president mostly involves getting Congresscritters to do things you like, so you can sign off on them. I lack charisma in that regard, people rarely listen to me until it's too late. Then I sit around moaning, "I told you so." I'd be a lousy president.