From Stan Greenberg:
I’ve seen tracking polls saying that Mitt Romney is either tied or leading in the presidential race, but we think that they are simply wrong. It’s not a conspiracy theory; those other polls are just simply missing a critical segment of President Obama’s coalition: cell phone users. Failing to survey those who don’t have land-lines — who tend to support the president by a significant margin — those polls are blind to the fact that Obama is on track to win re-election on November 6.
Full report here: http://www.democracycorps.com/...