Constitution doesn't allow it. You'll have to amend it.
Frankly, I'm sick and tired of the cowardice. We have a right of self-defense, but Americans apparently don't have the fortitude or character to exercise it. All the shouting, and all the people screaming to "ban guns" reject anything that might require them to take responsibility for themselves and their own security.
There are more guns than people in this nation. If we banned guns tomorrow school shootings would continue. Nobody on your side of it wants to acknowledge that the Nashville shooter changed the school they chose to target because security was too tight at their original choice. Cowards want daddy government to take care of them, and that is truly disgusting to me.