An unexpected figure has recently emerged as a possible candidate for the Republican presidential nomination in 2012. John Bolton, whom former President George W. Bush appointed as ambassador to the United Nations for 16 months -- despite never winning confirmation in the U.S. Senate -- has raised the possibility that he would be open to a presidential campaign to highlight foreign-policy issues. Bolton would be a heavy underdog if he enters the race, against a pack of high-profile candidates already looking to run -- including former Massachusetts Gov. Mitt Romney, former Arkansas Gov. Mike Huckabee, former Alaska Gov. Sarah Palin,...