Time Magazine will lead this week with a look at the rise of the younger voter, spurred to the polls by Barack Obama's star power. If that sounds familiar, replace the name "Barack Obama" with "Howard Dean" or any of the large number of candidates who supposedly have relied on the youth vote over the years, and one or many news outlets wrote the same story then.

Most candidates who rely on the youth vote end up disappointed at the end when younger voters don't bother showing up. But Obama remains a front-runner after big victories in two states. For all the talk of younger voters flocking toward their favored candidate, though, the numbers tell a less spectacular story: Yes, youth turnout is up. But, the numbers show, not that much.

Those between the ages of 17-29 who are eligible to caucus made up 22% of the Iowa electorate this year, up only 5 points from 2004. In New Hampshire, turnout among those 18-29 was 18%, up 4 points from four years ago. In South Carolina, the 14% of the electorate who are young was up 5 points.

Many more young people turned out this year, but turnout was up across the board, and youth voters rose only slightly more than the population at large. Perhaps more telling, younger voters are making up smaller portions of the electorate. Those under 29 made up just 9% in Florida, and the numbers have decreased in each successive state.

Obama is doing well among younger voters, but it's not a key portion of his coalition. Obama's success rests on a more traditional base of Democrats. As Gordon Fischer, a top Obama adviser and former Iowa Democratic Party chairman, told Politics Nation a few months ago, the youth vote is the icing on the cake, but the campaign is still baking the cake.

Finally, it seems, a campaign that the media says will benefit from a big youth boom is not letting the hype go to its head. Ask President Dean how much good the promise of a younger voter surge actually does.