Pipe bomb sent to Obama, Clinton stirrs question about vitriolic politics

Pipe bombs were sent to several prominent Democrats, including former President Barack Obama and former Secretary of State Hillary Clinton, setting off an intense investigation on Wednesday into whether figures vilified by the right were being targeted.

From Washington to New York to Florida to Los Angeles, the authorities intercepted a wave of crudely built devices that were contained in manila envelopes.

In the center of Manhattan, the Time Warner Center, an elegant office and shopping complex, was evacuated because of a pipe bomb sent to CNN, which has its New York offices there. It was addressed to John O. Brennan, a