Democratic President Barack Obama's top campaign lawyer filed a complaint with the federal election regulator on Tuesday, demanding that the well-heeded and high-spending Republican advocacy group Crossroads GPS disclose its donors... "There has never been any doubt about its true purpose: to elect candidates of its choice to the presidency and Congress," Obama campaign lawyer Robert Bauer wrote in his complaint to the FEC, posted online by the New York Times on Tuesday alongside the letter to Crossroads GPS that accompanied it.