If President Obama or former Secretary of State Clinton could appear in public and state that X measure would have stopped Y shooting, then that X measure would soar in public support.But they can't. So they don't. Instead they politicize these awful moments, speaking about straw men and magic, imaginary legislative solutions and now at least the president is willing to explicitly concede that he is doing exactly that.
See also: Time to talk about gun free zones: Lone gunmen have a fondness for places where victims won't shoot back.
Gun-free zones achieve the opposite of what is intended. Rather than making good people safer, it puts them at the mercy of the evil people.