State Police are investigating one of Mitt Romney's top campaign aides for allegedly impersonating a trooper by calling a Wilmington company and threatening to cite the driver of a company van for erratic driving, according to two law enforcement sources familiar with the probe. Jay Garrity, who is director of operations on Romney's presidential campaign and a constant presence at his side, became the primary target of the investigation, according to one of the sources, after authorities traced the cellphone used to make the call back to him. The investigation comes three years after Garrity, while working for Romney in...