Even for a nonconformist, Alaska Gov. Sarah Palin has defied political logic with her sudden, stunning announcement to leave office more than a year early.The announcement caught even current and former Palin advisers by surprise. Former members of Sen. John McCain's 2008 presidential campaign team, now dispersed across the country, traded perplexed e-mails and phone calls about the vice presidential nominee's decision to step down.In a hastily arranged news conference at her home in Wasilla, a suburb of Anchorage, Palin said she had decided against running for re-election as Alaska's governor, and believed it was best to leave office even though she had 1.5 years left to her term. Lt. Gov. Sean Parnell will take her place.On her Twitter page Friday evening, Palin wrote that she was remembering America's service members on the eve of Fourth of July.