"The Book of Mormon" debuted this year as a Broadway hit that won nine Tonys, and the 2012 race for the Republican presidential nomination features not one, but two candidates of the Mormon faith. Now the Church of Jesus Christ of Latter-day Saints is launching a major expansion of its "I'm a Mormon" advertising campaign, which, church officials say, seeks to educate the public and dispel myths about one of the fastest-growing religions in the world.