- "Likely voter" methodology - use of "expansive" model vs. standard model (that accounts for past voting behavior)
- Overweight Democrat samples based on a common assumption about expected '08 turnout that is at odds with recent electoral history.
- Known higher propensity for Democrats to answer polls.
- "Bradley Effect" - anomalous answers due to perceived social pressure.
My point is that if we accept the idea that McCain has a chance to win, then we must also believe that something very unusual is happening this year, such that the validity of all current polling methodology needs to be called into question. On the face of it, that would seem to be a stretch. But this year, it might just be true.
The “common factor” is the shedding of any appearance of objectivity in the media. The media/pollsters are in the tank for this rotten piece of human garbage like no other candidate in history. The unusual thing happening this year is the attempt at force-feeding us a candidate who opposes life and opposes the things that make America great.
Do they? We have a batch saying Obama leads by 8, 10 or even 15 points. That's laughable on its face, and completely unsupported by historical baselines and what we're witnessing in state-by-state campaigning. Then we have a group of polls showing a margin of error race. Which is what we have had for months and months, and what we're witnessing right now.