As a sidenote to Obama's 66-32 blowout among 18-29 voters, check out how these same voters voted for the House. Not much different: 63-34.
So, in casting an identity politics vote for Barack Obama, a hip young (by political standards) African American, young voters were also apt to vote straight ticket for the Democrats down ballot. Nor is this new: the 2004 Democratic margin in the House among these voters mirrored the Kerry vote (+11 for Democrats vs. +9 for Kerry).
People have been focusing on whether the youth vote was up. It was -- slightly: going from 17 to 18 percent. But the real story about the youth vote is not how many "new" voters Obama got to show up. It's how he produced a gargantuan 25% swing among existing young voters, or those who were sure to vote for the first time anyway.
18 percent times a 25 percent increase in the Democratic margin equals 4.5 points, or a majority of Obama's popular vote margin. Had the Democratic 18-29 vote stayed the same as 2004's already impressive percentage, Obama would have won by about 2 points, and would not have won 73 electoral votes from Florida, Ohio, North Carolina, or Indiana.
So, to clarify here: Obama's youth margin = 73 electoral votes. Without the economic crisis, this would have been the difference.
In the House, the youth margin for Democratic candidates was up 18 points from 2004 and 7 points from 2006 (with a 50% increase in the voter pool from '06). The 18-29 demographic's net contribution to Democratic margins in the House went from 12% x 22% = 2.64% in 2006, to 18% x 29% = 5.22% in 2008. How many of our guys lost by 2.6% or less? And it wasn't about "more" or "new" young voters. For the most part it was the same young voters, who were conditioned to vote for Democratic candidates after switching to Obama.
Related to this are African Americans. Here too, turnout was up a point from 12% to 13%, or Census + 1. But that's only part of the story. The biggest part is Obama's increased margins, moving from 88-11 in '04 to 95-4 in '08. The black vote's net contribution to Democrats moved from 9.7 points to 11.8 points (91% x 13%), or an increase of 2.1 points.
Now, let's be generous and shave 10% off the youth effect assuming some of these youths are African American, but also tempered by the fact that the young black vote is already so highly Democratic that a 25% swing is impossible here. 4.1 percent (18-29) + 2.1 percent (AA's) equals 6.2 percent. Obama's current popular vote margin is 6.1 percent.
Obama's entire popular vote majority is accounted for by his increased appeal to youth and African Americans.
This is not to say that a white male (or female) Democratic candidate would not have won the election. The youth and African American figures would have moved some, though not as strongly for them, and if it was Hillary, you'd have seen a similar phenomenon with women voters. So, simply transposing 2004 figures onto 2008 isn't the right baseline. But this is a dramatic statement nonetheless. Obama has reshaped the electorate. And it's been only partially through new voter registration. He has gobbled up every last, existing young voter and African American (FTW, I get the distinct sense that Condi Rice too voted for Obama).
For more in uplifting news, don't miss Greg Mankiw.