an axiom of american politics

From Evangelical Outpost:

Six months ago, how many pundits would have predicted that on the 1st day of 2008 there would be a four-way tie in the national polls between Giuliani, Huckabee, Romney, and McCain? The fact is that they don't know any more than you do. Indeed, the closer they are to DC, the less they are likely to know what actual voters are thinking.

And that doesn't only apply to pundits, of course.