If he were to do that, the cops and military could kick in the doors or illegal aliens without a warrant however, they would also have the power to kick in your door and confiscate your guns.
sorry, but I would be helping to round up the illegals....I know I would be able to keep my guns, and the second would probably not be suspended by declaring Martial Law, for to repel an invasion would demand America stay armed, unless hellery, or some other democrat was in office.