The violent video games argument is weak, I've looked into that. And if what you say is true, then why don't we see a ripple effect given America's influence on the world's media? Violent acts are more frequent due to terrorism - but we don't see the same kinds of mass shootings occur throughout the western world like we do in the US. 

I agree that the overall sentiment needs to change. What I have a big issue with is when people think that kind of rhetoric is endemic to a single political party. 

We've seen motivated mass murders of every stripe. But whenever it happens you see things like what Bill Hooper and GodBlessAmerica post. "This is all because of liberals just like the ones here in Eugene! They are the ones promoting hate and this won't stop until they do!" But if a conservative goes on a killing spree it's "Some people are just deranged, oh well. What can we do?" There's no entertaining the idea that extremism on either side is wrong, it's much easier to point to one side.