In the 2008 election, young people aged 18-29 voted overwhelmingly Democratic. The gap between Democratic candidates and Republican candidates was nearly 30%: 63% of young voters voted for Democratic candidates and only 34% for Republican. While the numbers for this past election still suggest that young voters predominantly vote Democratic--although the margin between Democrats and Republicans was smaller, 57% to 40%--fewer young voters turned out in 2010 as compared with 2008, and the Democratic Party noticed.
The young voter share of the electorate in 2010 was down 7% from 2008, falling from 18% to 11%. The Washington Post quotes Michael McDonald, a government professor at George Mason University who studies voting and turnout, as saying that "turnout for young people is always lower in a midterm election." That pattern may have been exacerbated by current disappointment with Democrats and "a lack of inspiration from candidates and the airing of negative ads [that turned off young voters]"
Even in fewer numbers, young voters played a very important role for Democrats in the 2010 midterm elections. Every other age group favored Republicans, with 59% of those over 65 (who made up 23% of the electorate in 2010, as compared with 15% in 2008) voting Republican.