Rasmussen vs Everyone Else

(Daily Dish h/t)

Just looking at this raft of polling data, it's perfectly clear that Rasmussen is polling a different country than other polling outfits.

Generic Congressional Vote
Polling Data

Poll	Date	Sample	Democrats	Republicans	Spread
RCP Average	10/1 - 10/18	--	45.0	39.5	Democrats +5.5
ABC News/Wash Post	10/15 - 10/18	1004 A	51	39	Democrats +12
Rasmussen Reports	10/12 - 10/18	3500 LV	37	42	Republicans +5
CBS News	10/5 - 10/8	RV	46	33	Democrats +13
Gallup	10/1 - 10/4	906 RV	46	44	Democrats +2

See All Generic Congressional Vote Polling Data

So it will be interesting to see where the facts lie after the votes are in for 2010. In other words, can a bias be shown with whom these organizations are polling?