Whatever the president does will just be window dressing. Mental illness is the issue. Any gun in the hands of a nut is a menace to everyone. Yet, the president's banning of certain types of guns and their magazines won't have any impact on mentally ill nuts who use any available gun to create mayhem.
Now, a complete news black out after a shooting would go a long way to prevent copy-cat incidents. But of course, there's this darn free speech issue.