WASHINGTON -- Conservatives, who reputedly have lumps of coal where their hearts should be, have fallen in love. So have many people who are not doctrinal conservatives. The world is a sweeter place because Sarah Palin has increased the quantity of love, but this is not a reliable foundation for John McCain's campaign. The tech bubble was followed by the housing bubble, which has been topped by the Palin bubble. Bubbles will always be with us, because irrational exuberance always will be. Its symptom is the assumption that old limits have yielded to undreamt-of possibilities: The Dow will always rise,...