invade Mexico, we educate them and provide health care invasion will secure natural resources and a smaller border

I would like to invade Mexcio, we spend billions of dollars every year on citizens of Mexcio in education and health care not to mention jobs why not just make them citizens of our country. we will then be able to access some of their resources like oil,we could add 7 or 8 new states which means more jobs for beauracrats . We would also have a much smaller border to secure.