Protecting Nate Silver

Alerted by Brad (“The Scoutmaster”) DeLongprotector of vulnerable young journalists!–the NYT‘s Paul Krugman defends Nate Silver’s election projections against a fairly calm critique in National Review.  I leave it to you, the reader, to decide if arguing that Silver includes too many old polls is the sort of thing that, allowed to proliferate, “means … science — or any kind of scholarship — will become impossible.”  But what surprised me was this Krugman graf:

It’s almost besides the point to notice that the whole notion that Nate Silver is somehow serving Obama’s interests by skewing the results is bizarre. This race is going to be decided by actual votes, not perceptions of “momentum”. But then posturing and bragging seems to be central to the right’s theory, for reasons I don’t get. [E.A.]

I thought the whole reason for the “momentum” wars–is Mitt surging or not?–is that the perception of momentum can easily become self-fulfilling, because undecided voters tend to break toward the candidate they think is the likely “winner.” It’s not just “posturing and bragging”–though there’s plenty of that.  It might affect “actual votes.” If Krugman doesn’t understand that, what else …