Also, he says the true Iowa numbers are realistically like this:
CANDIDATE SUPPORT IN IOWA
Undecided 80%
Donald Trump 5%
Ben Carson 4%
Ted Cruz 3%
Marco Rubio 2%
Jeb Bush 1%
Carly Fiorina 1%
Mike Huckabee 1%
Chris Christie 1%
He's pretty much just pulling numbers out from where the sun don't shine at this point.
Silver just went full Dick Morris with this nonsense.
He fails to distinguish betweens true "undecideds" and the fact that some people change their minds during a campaign. The fact that of the 30% that currently support Trump, a fair bunch of them might very well end up supporting someone else does not mean that they are "undecided". They have decided for now, but they might chance their mind. The difference is that they have to be swayed to change their mind. Up until now, increased exposure hasn't hurt Trump one iota.
Anyway, Silver seems to have forgotten what got him his glory in the first place. It was ignoring gut feelings and the usual punditry and sticking to crunching numbers. Silver always argued that polls matter and now he seems to be arguing the opposite. He seems to be operating from his initial assumption that "Trump can't win" - like most other pundits - and desperately looks for any indication or argument that can support this gut feeling. That is just bad science and the exact opposite of what Silver is known for.
Now, I think there are still plenty of good reasons why Trump might not win the nomination, but saying that his chances are way below 20% at this point rings untrue when you look at his constant domination of all relevant polls since july.
