In my case I guess my most lib moment was thinking Obama would follow through on any of his campaign promises (and believing he was somehow the anti-war candidate close guantanamo etc).
I think a lot of it was the recession hit my family hard, and when you're a high school kid and the "smart" people on TV say its Obama's fault you just accept it. Not that that's any excuse but just goes to show how easily people are influenced.
I actually cannot believe 18 year olds vote, I didn't have a mature view on the world till I was at least 22 or 23.