In 1968 the Democrats won 47% of the (21) to 29 year old vote, in 1972, they won 46% of the 18 to 29 age group, in 1976, after Watergate, and with the weak, moderate (and under suspicion) Ford, against what appeared to be a social conservative Democrat with a strong military back ground, the Democrats picked up 51% of the 18 to 29 year old vote.
In 1980 Democrats got 44% of that age group, 1984-40%, 1988-47%.
It wasn’t until 1992 that the under 30 age group became a Democrat voter group, George W. did get 46% and 45% though.
The 66% that Obama won, is unprecedented and doesn’t bode well for the future.
“Youth” has very little to do with this voting pattern.
Race is the key issue.
In 2014, almost half of all 18 year olds will be non-white.
Fact is, young people vote very much like their parents, and non-white parents vote overwhelmingly for Democrats.
Republicans have only themselves to blame for this political catastrophe.
Since the Reagan Amnesty in 1986, the GOP has agreed to 3 more smaller Amnesties, and we agreed to massive increases in work visas, Green Cards, and new naturalized citizens.
The political bill for those reckless decisions has now come due.
2012 - Obama’s youth vote came down to 60%.
The 4 million white voters who “stayed home” in 2012 are most likely young whites who voted for Obama in 2008.
But, as you say, long term, the political future for Conservatives looks very grim.