ROCK HILL, S.C. — As Sarah Palin wonders whether to run for president, she might want to talk to people in places such as South Carolina. She'd find her star fading, and her prospects daunting. Republicans still like her, but now they openly question whether she could or should be nominated for president, let alone elected. At a recent gathering in South Carolina, the site of a crucial early presidential primary next year, party activists said the former Alaska governor didn't have the experience, the knowledge of issues or the ability to get beyond folksy slang and bumper-sticker generalities that...