Gallup overtakes Gravis and Rasmussen as pollster with biggest RW tilt
These are pollsters' "house effects" as updated today in Pollster.com.
A large house effect (at the bottom of at the top of the list) does not necessarily mean the pollster is inaccurate. house effect is the deviation from the average of all pollsters. Only after the elections will we know which of these pollsters was the best; however, it tells you something about how ridiculous Gallup is: