Interesting: For 8 years, Gallup polls consistently put presidential approval

[DLnyc]

several points higher than mainstream polls. But now they've swung the other way and are polling several points BELOW everyone else. I wonder why that is?

See Professor Pollkatz's wonderful graph showing Gallup very consistently above the rest of the pack during 2001 - 2008 (Gallup's are the purple diamonds riding the top of the (falling) trend:


Now look at PollingReport.com 2009 numbers from Gallup:
http://www.pollingreport.com/obama_job.htm#Gallup
versus the rest of the pack:
http://www.pollingreport.com/obama_job.htm

Why in the world could that be?

[Warpy]

1. We've known that Gallup has overweighted in favor of GOPs for years

the only thing surprising to me about that graph is how centrist Pox News is.

I tend to turn my nose up at all of them but Harris and Ipsos-Reid.

[Alexander]

2. They look purple, not red.

And I wonder if American Research Group is now polling Obama slightly higher than average.

[DLnyc]

3. Okay, I stand corrected.

I will change it to purple in the OP.

[Alexander]

4. I agree with your point though. Gallup has been known to oversample Republicans.

[DLnyc]

5. Yeah, I've always considered them weighted. But this particular discrepancy

as amusingly obvious.