The references to the bombing of the Alfred P. Murrah Federal Building in Oklahoma City in 1995 echoed in other ways. That horror, which killed 168 people including many children, helped then-President Bill Clinton stigmatize extreme anti-government rhetoric and re-energize his presidency at a time when Newt Gingrich and conservative Republicans were riding high in Congress. One veteran Democratic operative, who blames overheated rhetoric for the shooting, said President Barack Obama should carefully but forcefully do what his predecessor did. "They need to deftly pin this on the tea partiers," said the Democrat. "Just like the Clinton White House deftly...