Olympic superstar and Kardashian clan member Caitlyn Jenner said Friday she filed paperwork to run for governor of California, in a bid to become the first transgender American to win such a high-profile post. "I'm in!" the 71-year-old former decathlete said in a statement, adding she will formally launch her campaign -- presumably as a Republican -- at a later date. "I am a proven winner and the only outsider who can put an end to (Democrat) Gavin Newsom's disastrous time as governor," she added. mlm/dw