A senior vice president of CBS News, Paul Friedman, said the prospects for Barack Obama or John McCain meeting the minimum threshold of electoral votes could be clear as soon as 8 p.m. — before polls in even New York and Rhode Island close, let alone those in Texas and California. At such a moment, determined from a combination of polling data and samples of actual votes, the network could share its preliminary projection with viewers, Mr. Friedman said.

Reviewing Fox News/Rasmussen Reports data from key battleground states raises a couple red flags about the use of early exit polling data to predict a winner. Understanding this data from polling conducted last Sunday night may save some a repeat of 2004’s heartache.

The bottom line is that in every state we polled—Colorado, Florida, Missouri, North Carolina, Ohio and Virginia— Democrats are a lot more eager to take exit polls than Republicans.

In five of the six states, a majority of Democrats say they would be Very Likely to participate in the exit polling process. At the same time, in five of the six states, fewer than 40% of Republicans would be willing to do the same.

In every state, Republicans are at least twice as likely as Democrats to say that they are not at all willing to take an exit poll.

Unaffiliated voters tend to align more closely to Republicans in all six states in both willingness and unwillingness to participate in exit polls.

Part of the frustration may stem from the fact that the primary value of exit polling is to help us understand why people voted the way they did. This is an entirely different task than trying to predict a winner for Internet junkies who can’t wait a few more hours until actual votes are counted.