Some polls show hypothetical Tea Party candidates with more support than Democrats or Republicans, but the key word is “hypothetical.” As the Tea Party Convention begins today in Nashville, it's not clear that any candidate could get away with claiming “Tea Party” association. Republicans are trying to focus their anger, but tea-partiers lump both major parties into one, hated Establishment. Why have so many original organizers pulled out of this week's convention? Will Sarah Palin damage her image by appearing and taking a big fee? Will the convention define a political movement or dramatize differences that can't be resolved?