CONCORD -- More than half a million voters could turn out in today's New Hampshire primary, turnout statistics and the Secretary of State said yesterday. That astounding number will affect the outcomes of both races, though who turns out remains an open question.

In 2000, the last time both parties had primaries, 44% of New Hampshire's eligible voting population turned out. That number is impressive in itself: It's only slightly lower than the national average for general presidential elections. Eight years ago, that equaled 396,000 people. After an explosion that has seen the state's population rise nearly 30% in the intervening time, a similar turnout percentage would equal just over 500,000 people.

Still, this year Iowa saw a much higher turnout than expected, roughly double the number of Democrats who showed up in 2004 and a sizable improvement from 2000 for the GOP as well. With both parties facing competitive elections and multiple candidates targeting the youth vote at colleges and high schools around the state, it is highly probable that, like Iowa, New Hampshire will see a much bigger turnout than any previous year.

With such a high turnout expected, no campaign really knows what to do. None would offer turnout estimates, even privately. We'll provide updates throughout the day as the campaigns get a handle on the ground game. Some votes have already been cast: We ran into more than a few wise voters who picked up an absentee ballot today in order to get the ordeal over with. Expect long lines, Granite Staters, if you plan to cast a ballot tomorrow.