I know the Gallup poll is one of the "respectable" polls, but lately it has been running 9% and 11% swings within very short periods of time -- sometimes within a single day. Part of this is due to it's "likely voter model". "Likely voter" is a fuzzy concept to begin with. But Gallup tries to refine it by measuring enthusiam. I.E. an enthusiastic voter is more likely to vote. (I doubt this is always true. Carroll may be the ultimate unethusiastic voter -- but I would bet he generally votes on election day -- if only to cast a blank ballot or vote for Donald Duck.) So Gallup is trying extend a fuzzy concept with a subjective paradigm. This sounds more like bad sex than good polling.