These thoughts by Timothy Egan and these from Jonathan Chait @ TNR add to the current discussion about the effect of incendiary or outright hate speech. The piece from TNR raises a good point: to say that discourse should become more civil and less incendiary is different from trying to "limit free speech". There's a difference, a crucial difference, between norms (voluntary, governed by social convention) and laws (enforced by the coercive power of the state). I don't want to limit free speech, which is to say I don't think that the government should normally control what people can say. However, by the use of social norms, I suggest that we can and should limit such speech. How? Don't listen to it (e.g., Rush Limbaugh or Glen Beck, who get paid according to their ratings). I wouldn't let someone use my blog space to spew hatred or invective. Remember, "free speech" is a matter of legal rights that limit government action and not a compulsory requirement for individuals or private entities.
I truly believe that spirited public discourse can be fruitful in a democracy. However, invective, calling into question the legitimacy of an adversary, grade-school level name-calling--all of that is unnecessary and stupid. (How's that for invective!)
Finally, we are influenced by words. Some--especially the mentally limited or deranged--more than others. We like to think that "sticks and stones will break my bones, but words will never hurt me". But you know that's not true. Please write in if you've never been cut by words. Please write if you have reacted viscerally to some report that has later proven false or incomplete. Let's face it, humans, we're all suckers for words. We need to have our crap-detectors on 24/7, but it's not easy. Think of the incredible karma for words, how they are all mustard seeds. Some blow away in the wind, some grow a bit and die, but some, in the right conditions, come to fruition, for good or ill. Please! Sow carefully.