As a member of the 18-30 aged group, I have to say that many members of my generation call themselves liberals even if they aren't. Many hold fairly conservative views but don't call themselves Republicans due to the tarnished name the party carries. I would say that my group is moderate on economics, 50-50 split on abortion, but very pro-gay rights.
One of the things I can't stand is this idea that Republicans need to moderate their position on the so called "gay rights" to appeal to young voters. There is absolutely no evidenced that many people voted for Obama because McCain opposed gay marriage. The problem is that most of our "opinion making class" (and I daresay a dispoportionate amount of political activists on the internet) come from liberal enclaves that do not share the rest of the nation's values. The ral problem is the failure of Republican governance the last eight years.
I wouldn't say that young people voted for Obama over Mccain due to issues over gay rights, but it is undeniable that young people are vastly more liberal on this issue than the public at large. And the ones who are most conservative are the ones who are the oldest. So it is quite obvious that the nation will become much more liberal on this issue and fast. Republicans have to moderate on this issue, like at least supporting civil unions, or they will be looked at as bigots. There is no other way to put this.