Was President Obama encouraging murder during his 2008 campaign when he said, “If they bring a knife … we bring a gun”? Was he encouraging political violence when he said more recently of the new Republican House majority that “we are going to have just hand-to-hand combat up here on Capitol Hill”? Of course not. Similarly, former Pennsylvania Democratic Rep. Paul Kanjorski was speaking allegorically in October when he said Florida Republican gubernatorial candidate Rick Scott should “be lined up against a wall and shot.” Such remarks are often hackneyed or tasteless, but reasonable people understand they are not incitements to violence. Jared Loughner, the gunman charged with wounding Rep. Gabrielle Giffords, D-Ariz., and murdering six others in Tucson on Saturday, held bizarre beliefs about “conscious dreaming” and government mind control imposed through English grammar. No serious person would connect his belief system to a mainstream political ideology. But then there’s New York Times columnist Paul Krugman. He places the blood libel of blame for the Tucson murders squarely on the shoulders of “the crowds at the McCain-Palin rallies” and “right-wing extremism.” It’s the Republicans’ fault because “the purveyors of hate have been treated with respect, even deference, by the GOP establishment.” Krugman’s solution is for “decent people” to “shun” those he holds accountable. But the logic of his argument leads straight to calling for official restrictions on political speech after shunning inevitably fails to do the job. The totalitarian temptation is an ever-present possibility with people like Krugman.

Another self-righteous voice in this debate is left-wing blogger Markos Moulitsas, who said in June 2008 that he was placing a “bull’s-eye” on Giffords’ and other Democratic moderates’ districts because of their vote on an intelligence bill, by which they had “sold out the Constitution.” Last week, a Kos diarist even wrote an angry rant about Giffords, declaring, “My CongressWOMAN voted against Nancy Pelosi! And is now DEAD to me!”