Liberal columnists like Paul Krugman have sought to scapegoat conservatives for the recent shootings in Tucson. But the shooter was once described as a "liberal pothead," and the "Communist Manifesto" was one of his favorite books. There is no evidence he was influenced by any contemporary political rhetoric.
Moreover, harsh rhetoric comes mostly from liberals like former Rep. Paul Kanjorski, D-Pa., who said of Florida Gov. Rick Scott: "They ought to put him against a wall and shoot him." Yet the New York Times recently published an editorial by Kanjorski whining about "incivility," contradicting claims by its own columnist that "it's hard to imagine a Democratic member of Congress urging constituents to be 'armed and dangerous' without being ostracized."
Kanjorski wasn't criticized, much less ostracized, by the Times for promoting violence. Instead, it gave him a soapbox.