In effect, Silver is picking off all the poll results he doesn't like, while blowing off all the methodological problems with the ones that he does like. What was it that Mark Twain quoted of Benjamin Disraeli? "There are three kinds of lies: lies, damned lies, and statistics." The general thought holds for statisticians, too. Wearing a white lab coat doesn't turn anyone into a scientist.
http://news.yahoo.com/other-polls-show-tight-race-gallup-stands-apart-020811767.html
The liberal press will doubt and downplay any poll that does not show their savior leading. They had better get used to saying President Romney.