I've not especially followed the Bad Rhetoric = Violent Massacre stuff.
Yes, wingnut rhetoric is dangerous and irresponsible and loony.
But worrying about whether or not wingnut rhetoric is responsible for the Tucson nutjob, well, that's like worrying about shutting the barn door after the horse has been shot and fucked and sold for glue.
Surely: this shooting was horrific.
But then, wingnut rhetoric has directly led to mind-boggling numbers of deaths in Iraq and Afghanistan; it's ruined the American economy; it's made torture routine; it has succeeded in preventing the nation from taking effective action to prevent environmental catastrophe.
Busting wingnut rhetoric for these latest shootings wouldn't be like busting Al Capone for tax evasion. It would be like busting Al Capone for fucking jaywalking.
The reason the Tucson nightmare fearfully resonates is not because of a simple causal relationship between say Glenn Beck and direct incitements to murder, but because "conservatives" have an insatiable appetite for crazy bullshit.
Are wingnuts opposed to incitement to murder because, well, it's incitement to murder, or because they're afraid being caught out doing it might lose them Valuable Political Points?
Dunno! But once you've gone ahead and, say, made excuses for state-sponsored torture, if you want the benefit of the doubt, fuck you.