They haven't done much. And neither have democrats (what dems HAVE done has mostly been counterproductive and pandering). But, for both sides, lack of meaningful action isn't because they are bad people with bad intentions, or that they are in the pocket of some interest or another...it is because it is a very difficult issue. Freedom and rights colliding with safety is a messy arena, and has been for as long as this country has existed. Contrary to popular sentiment, there are very few, if any, common sense fixes that can be quickly implemented to address or prevent these tragic events. Even ardent supporters of gun control measures concede that they almost universally would not prevent events that we are reacting to, but fall back on the "we at least need to do SOMETHING" mantra. But that is not a good enough reason to trample constitutional rights or to restrict other citizens ability to acquire means to defend themselves and their families. Whatever we do needs to be well reasoned, evidence based, and preserve the rights of law abiding citizens. And we need to also be cognizant that in a country of 300+ million people, there are going to be anti-social psychopaths perpetrating horrific events from time to time...and while we should by no means just throw our hands up about it, we should also not knee-jerk with half-baked, draconian measures when it happens.