The memorable massacres of history have been the stuff of ruthless despots. They're about power and intolerance -- getting rid of anyone who could cause trouble. Attila the Hun needed an army to massacre his enemy. Josef Stalin was a wholesale killer who measured his dead in the millions.
By now the script should be familiar. A bombing or a mass shooting occurs and the media immediately look for a simple cause. Invariably, they turn to talk radio or some other conservative pit of "intolerance."