American berserk: The attack at Nancy Pelosi’s home is the latest symptom of politics off the rails

A man who marinated in the stew of virulent right-wing rhetoric allegedly broke into the San Francisco home of the speaker of the U.S. House, shouted “Where is Nancy?” and then brutalized her husband Paul with a hammer. A nation that’s seen the shooting of Gabby Giffords and Steve Scalise, where threats and intimidation against members of Congress have been rising rapidly, can hardly act surprised, but we must not lose our capacity for outrage. Nor should we mince words about who is responsible for the current climate. While American politics has been dangerously divisive for decades, it’s Don...