The other faction is young women 19 to 34 who have a high unemployment rate (compared to other women their age in prior periods) and who are literally delaying having babies ~ which they want ~ because those young men they might marry, or to whom they're already married, don't have jobs.
Republicans have a shot with first time voters, especially those who can't find full-time work. But a swing demographic has to be one that goes to the polls, that votes for major party candidates, and is willing to switch to your party.
A lot of young people don't vote and others may go for a third party. Voters about 30 who went for Kerry and Obama and think of everything in terms of Bush also aren't likely to choose the GOP.
Also the problem with voting trends is they only really get confirmed later. Reagan did well with twentysomethings in 1980 (many thirtysomethings who were still thinking about Vietnam, student protest, and Watergate were still voting against Nixon so Reagan didn't do as well with them), but the trend was really noticeable in 1984 when the younger voters stuck with Reagan.
So, yes, younger voters are a valuable swing demographics, but probably older voters who went for Bush and then switched to Obama may be a better prospect for Republicans. So are those demographics who weren't as strong for Obama as for other Democrats, working-class White middle Americans, I guess.
Those are the famous "hard hats" who voted for George C. Wallace in 1968 and put Nixon in the White House ... then voted for Nixon himself, then Reagan in 1980. They're probably one of the most available groups, since they have jobs and families, and many of them have served in the military. Their polar opposites, single women with advanced degrees who never served in the military and never married, are the hardcore Democratic Progs I wrote about above.