The NY Times’ David Leonhardt points to some data collected by the Anti-Defamation League today to make the point that the right has a violence problem . Over the past decade, the Anti-Defamation League [has counted] about 450 U.S. murders committed by political extremists. Of these 450 killings, right-wing extremists committed about 75 percent. Islamic extremists were responsible for about 20 percent, and left-wing extremists were responsible for 4 percent. Nearly half of the murders were specifically tied to white supremacists… As this data shows, the American political right has a violence problem that has no equivalent on the left....