'...Since Obama’s ascension, we’ve seen repeated incidents of political violence. Just a short list would include the 2009 killing of three Pittsburgh police officers by a neo-Nazi Obama-hater; last year’s murder-suicide kamikaze attack on an I.R.S. office in Austin, Tex.; and the California police shootout with an assailant plotting to attack an obscure liberal foundation obsessively vilified by Beck. Obama said, correctly, on Wednesday that “a simple lack of civility” didn’t cause the Tucson tragedy. It didn’t cause these other incidents either. What did inform the earlier violence — including the vandalism at Giffords’s office — was an antigovernment radicalism as rabid on the right now as it was on the left in the late 1960s.'