Oops! To cap off his four-year campaign to win Iowa's Democratic caucus Thursday night, John Edwards planned a 36-hour marathon bus tour through 15 of the crucial state's 99 counties with a whole series of policy announcements to garner publicity and caucus votes. But 12 hours into the political odyssey -- billed as Edwards' "Marathon for the Middle Class" -- his Main Street Express bus began making very disturbing noises in western Iowa. In darkness, the bus with the entire Edwards entourage pulled over at a service station and was abandoned. Oh, the awful symbolism for a political campaign struggling...