Charlie's just annoying because he's behind a paywall. Sabato is really awesome -- of the 'mainstream' pundits, he's probably the best out there -- and Nate Silver is pretty good too, though Silver is more interested in the mathematics than the politics and sometimes it can show.
Many Romney supporters are simply not interested in talking to pollsters.
As I previously coined it, The Obama Effect.
You actually know that silent majorities don't exist, don't you?
What reasons could have Romney supporters to lie in a massive way?
Occasionally, they do (two examples I can think of off the top of my head are the California gubernatorial election 1982 and the UK parliamentary election 1992); there's just doesn't seem to be any reason to think there is one in 2012. Though, they're called 'silent' for a reason.
