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. Supporters and critics alike say the former GOP vice presidential candidate's resignation, announced Friday afternoon and effective July 26, is an inexplicable move for a high profile Republican widely seen as a contender for a White House run in 2012. A half-term governor campaigning for president? "If she is thinking that leaving her term 16 months early is going to help her prepare to maybe go on to bigger and better things on the political...