In January, Philip McHarris was driving from New Haven to Boston to visit a friend when he saw a familiar sight in his rearview mirror — flashing police lights. It was late at night, and McHarris pulled into a gas station and waited, as he had done many times before, for the state trooper to approach his window. The problem, the trooper said, was the way McHarris had pulled off at an exit. Then he said that the highway where McHarris had been driving was a drug trafficking route, and asked if he could search the car for drugs.McHarris explained that he was a Ph.D. student in sociology and...…In January, Philip McHarris was driving from New Haven to Boston to visit a friend when he saw a familiar sight in his rearview mirror — flashing police lights. It was late at night, and McHarris pulled into a gas station and waited, as he had done many times before, for the state trooper to approach his window. The problem, the trooper said, was the way McHarris had pulled off at an exit. Then he said that the highway where McHarris had been driving was a drug trafficking route, and asked if he could search the car for drugs.McHarris explained that he was a Ph.D. student in sociology and...WW…