Pundits and politicians alike praised President Obama's speech at the Tucson memorial service last Wednesday. "A wonderful speech," wrote the New York Times' David Brooks. "A magnificent performance," wrote National Review's Rich Lowry. "A terrific speech," wrote Sen. John McCain. And those were just the voices on the right. Obama's tribute to the victims of the shooting and the heroism of bystanders was appreciated by everyone. But many conservatives particularly admired the speech because the president took care to say, in clear terms, that political rhetoric did not cause the violence in Tucson. "It did not," Obama said flatly. After...