If there’s one thing almost every species of political journalist agrees upon — number-crunchy nerds and shoe-leather reporters have no real beef about this — it’s that Iowa matters. Iowa matters a lot. …
It isn’t self-evident why the votes of a couple of hundred thousand people in a kooky caucus process in a demographically unrepresentative state should tell us all that much about what will happen in the rest of the country. So what follows is an inventory of theories as to why Iowa can matter and whether there’s any basis to think it might be more or less important than usual this year. CONT.
Nate Silver, FiveThirtyEight