SANTA FE, N.M. (AP) — Author and film producer George R. R. Martin waded into the politics of movie-industry tax breaks on Thursday while endorsing a prominent Democratic candidate for governor of New Mexico. Martin, a longtime Santa Fe resident and author of fantasy novels behind the "Game of Thrones" television series, made a plea to raise or eliminate New Mexico's $50 million annual limit on the state's tax incentive for film production.