Tufts looked at the youth vote in several swingy Senate states this year. The rise in youth particpation from 2010 to 2012 was usually pretty dramatic (in many cases doubling). This really undescores Democrat's need to create a situation where 2014 resembles 2012 as much as possible. Also worth noting for Democrats in that in many states, the youth vote is notably less white than the overall population.
It klooks like they have PDF reports for every state (just change the state abbrevaitions in the URL's). I just chose the big races to post here.
Louisiana:18-29 Voter Turnout:
'10- 26%
'12- 52%
Youth share of electorate:
'10- 13%
'12- 19%
North Carolina:18-29 Voter Turnout:
'10- 24%
'12- 57%
Youth share of electorate:
'10- 11%
'12- 16%
Arkansas:18-29 Voter Turnout:
'10- 18%
'12- 30%
Youth share of electorate:
'10- 8%
'12- 19%
Georgia:18-29 Voter Turnout:
'10- 24%
'12- 47%
Youth share of electorate:
'10- NA
'12- 19%
Colorado:18-29 Voter Turnout:
'10- 30%
'12- 56%
Youth share of electorate:
'10- 13%
'12- 20%
Iowa:18-29 Voter Turnout:
'10- 29%
'12- 57%
Youth share of electorate:
'10- 10%
'12- 25%