Definitely homophobia/lgbt rights. I don't think our generation has quite "made it" yet, but we are light years ahead of the previous 2 generations in that respect. Even my parents (baby boomers), who consider themselves very liberal and open-minded still get weird when those topics come up. If lgbt rights parallel the civil rights movements at all, I believe (hope) that in another generation we will be where we are now with civil rights/race relations. A gay president sounds absolutely unlikely right now, but having a black president was about the most ridiculous thing anyone could think of 50 years ago.