From The Federalist:

Campus carry is simply an extension of our natural right of self-defense. Our right to life follows us wherever we go, so the right to defend our lives must also accompany us. Whether I am at home, in my car, at work, or in the classroom, I possess the absolute and unrelenting right to defend myself against unjust aggression. Because firearms enhance that right, there exists a strong presumption in favor of being allowed to own and carry a firearm as I go about my daily business.