Spree, its difficult to explain such widely divergent results. My best guess is that they probably reflect a marginal swing group (10 percent or so) that is highly influenced by daily or weekly events and whose perceptions can shift on an almost daily basis.
Also, need to compare apples to apples, e.g., "likely" voter results are not comparable to "registered" voters. Date of poll can also be important and whether Nader/other third parties are included.
News 
Market Data 
Discover 
AI
