Pretty sure young white males favored Romney. It’s the single white females that are the problem.
http://townhall.com/columnists/michaelmedved/2013/03/27/missing-republicans—found-n1550038/page/full
...Even more startling, young people who happened to be white still comprised a big majority (61%) of all voters below the age of 30 and delivered a shocking, counter-intuitive verdict on the choice between the ineffably cool Barack and the hopelessly square Mitt: going for the Mormon grandfather of 18 by a decisive, near-landslide margin of 7 points.
In fact, the entire basis for Barack Obama’s strength among young voters in general stemmed from the disproportionate presence among them of blacks, Latinos and Asians—groups that tilted lopsidedly toward Obama.
Non-whites comprised 39% of the youth vote but only 28% of the overall electorate, so it’s hardly surprising that Romney would score a smaller overall percentage of these ballots from under-30 citizens.
Romney’s loss of young voters, in other words, reflects racial politics far more plausibly than any universal surge of youthful progressivism...