The grotesque shootings in Tucson (in my home state of Arizona) are incredibly upsetting, and the full facts are far from clear at this point. There will certainly be needed public-policy conversations about mental health treatment, gun control, and security for public officials. There will also be conversations, some productive and some not, about the role of harsh political rhetoric.
I wrote about that last sensitive topic back in April 2010, and I'd ask you to go back and take a look at that article.
I'll have more to say on that piece of the tragedy soon.