The details are still emerging, but it appears as though a terrorist attacked London. An attacker drove his car into a crowd on Westminster Bridge, near Big Ben, and killed five people while wounding as many as 40. This is tragic news, and the victims have my prayers. Unfortunately, what tends to happen — even before the dead are buried and often before many basic facts are known — is the same acrimonious debate.

Side A says that this incident will be used by racists and xenophobic individuals to spread more hatred. They worry that refugees and displaced persons will no longer be accepted. They point to Christian notions of love that should motivate the response to humanity despite an occasional nut that might tarnish the entire group. Sometimes they blame an atmosphere of hatred and intolerance. For example, even though President John F. Kennedy was shot by an avowed Communist, there are some who blame the “right-wing climate of hatred” for his murder. The targets on a Sarah Palin political ad become the motivation for the shooting of Rep. Gabrielle Giffords. And so on.