PHILADELPHIA — Wearing a bright smile, Kathy Barnette shook hands and introduced herself around the patio of a Montgomery County country club: “I’m Kathy, and I’m running for United States Senate,” she said. But many already knew that. ”People are hearing my story,” she told one voter Monday. “The momentum has been amazing.” Few would disagree. Running on a shoestring budget and with a personal story that begins on an Alabama pig farm, Barnette has rocketed to the forefront of Pennsylvania’s crucial Republican Senate primary, according to both public and private polling. She’s picked up late m...