Patrick Ruffini on the youth vote:

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. How big? 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.