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, where a congresswoman who is the former chairwoman of the Democratic National Committee has her office, the authorities intercepted a wave of crudely built devices that were contained in manila envelopes. Some bomb technicians who studied photos of the device that circulated on social media suggested that the bomb sent to CNN had hallmarks of fake...