The shooting in Arizona, as tragic as it is, illustrates one point precisely. 

When the progressives were using violent rhetoric, including calls to kill Bush, there wasn't one single conservative calling for the elimination of free speech, including theirs. 

When the shooting occured in Arizona, the progressives have called for elimination of the First Amendment in so far as it protects free speech for conservatives.  Even though they cannot site one single piece of evidence that the shooter was provoked by conservative speech, they still think that the First Amendment needs to be quashed.  For conservatives only, of course. 

There isn't a better example of the differences between progressives and conservatives.  We conservatives believe that the Constitution is a bedrock of our society and our greatness and applies to every citizen in America.  Progressives believe that the Constitution is simply a 200 year old piece of paper that doesn't really mean anything at all.