Imho, American culture has become more blatantly nasty in the past decade or so.
I'm inclined to think that Rosseau and/or other romantics bought the dynamite and Limbaugh lit the fuse.
The problem (and I think it's a very real problem) is that the classic ideal of a good life is one of restraining a lot of impulses. If you accept the romantic idea that there's a lot of truth and value in those repressed impulses (and I agree that there is), you're eventually thrown up against the fact that not all of those impulses are anything you really want to live with.
In effect, it's ok to come out of the closet about wanting to humiliate people. We have smug, unshameable bullies. In public. I don't think the US used to be like this.
I don't know what the way out is. I believe that some of the repressed impulses (frex, for gay sex) are actually better allowed out in public, so it's not just a matter of going back to some past set of standards.
Further thought: The whole troll/American Idol thing is dependent on some people still being vulnerable to shame.