In terms of "violent porn," I have to say that, although I would personally find it very disturbing, I can't agree with making it illegal. At least, not unless the violent porn in question was made with unwilling participants. That is clearly illegal because it would be actual rape, assault, ect. If we're talking about staged photography or film, where people are playing parts and there's no real harm done, there's no victim and no reason to make it illegal.

A little closer to home, if we're talking about artwork, there's clearly no victim and no reason to make it illegal. I can't agree with any law that just about criminalizes thought. Just because you don't like the subject matter (and in this case, I don't!), that doesn't mean that it's wrong and it doesn't mean that it should be outlawed. Only when there are real victims should laws be made and exercised to discourage the acts from happening.

As for the political situation in the US, I agree with everything Sealtm2 had to say.