No Way to Predict Size of GOP Gains

Polls are showing a huge range of possible results for tomorrow, with generic ballots suggesting anything from a 15-point Republican lead to a 3-point Democratic lead. “The fact is that there’s not really any way to say who’s right,” writes FiveThirtyEight polling guru Nate Silver in the New York Times. Even his own highly sophisticated model offers a wide range of outcomes: Last night it predicted a gain of 53 seats for the GOP, but its "95% confidence interval" runs from 23 seats to 81.

We do know that “Tuesday’s probably going to be a really good night for Republicans, but we really don’t have a very good idea of exactly how good.” To guess “within a range of 5 or 10 seats isn’t science—it’s superstition,” he writes. Silver can, however, show that things haven’t changed much for the Dems this year; their big drop in popularity, if you crunch the poll numbers, occurred in early 2009.
(More Election 2010 stories.)