It may seem like Democrats should be pretty happy with young voters. After all, President Obama twice won at least 60 percent of voters between the age of 18 and 29 -- outpacing all other presidential candidates spanning the last three decades.

But a closer look reveals some troubling signs for the party. Young voter turnout is nothing like it was in the 1980s and early 1990s. And the stagnation has been driven by an across-the-board disinterest among several demographic groups. It's a potential problem for Democrats, because we're talking about a slice of the electorate which has sided with the party during the last six presidential elections.

Just 41 percent of eligible voters aged 18-24 cast ballots the 2012 presidential election, according to a Census Bureau report released this week. That's lower than any other age group, and 21 points below the overall turnout rate of 62 percent.

Turnout among 18-24 year-olds was also down across the board, compared to 2008.

It's not as if there has been a single driver of poor youth turnout. Consider the breakdown of the youth vote by race. Asians and Hispanics make up 18 percent of the age 18-24 citizen population, a much higher proportion than in the overall citizen population (11 percent). And they turned out at somewhat lower rates.

But turnout among young whites and blacks also lagged behind. Just 42 percent of young whites turned out, compared to 64 percent of whites overall. Turnout among young blacks was 17 points below the rate for all blacks.

Things weren't always this way. Voters aged 18-29 made up nearly a quarter of the electorate in 1984. Since then, their share of the electorate has declined steadily. The Census Bureau survey found voters aged 18-29 made up just 15 percent of the 2012 electorate -- lower than exit poll data have shown for the past few elections.

A common misconception about Obama is that he drove far more young voters to the polls in 2008 compared to recent elections. That's not the case. What is true is that he dominated among voters aged 18-29 in a way that other recent presidential candidates could only dream about.

That's precisely why young voters' broadly low participation is a problem for the Democratic Party. Here is a group that by and large votes Democratic. The more the party can grow the pool of younger votes, the better it is likely to fare overall. Conversely, the smaller the pool becomes, the better it is for Republicans, who don't fare so well with the youth vote.

The lack of young voter participation seems to speak to the widespread disillusionment of about politics more generally. These young voters have come of age at a time in which polling shows extraordinarily low trust in government among Americans. Moving forward, the big question is whether they will ever catch up to their elders.

Clement is a pollster with Capital Insight, the independent polling group of Washington Post Media.