"I have to tell you that over the course of several years as I have talked to friends and family and neighbors when I think about members of my own staff who are in incredibly committed monogamous relationships, same-sex relationships, who are raising kids together, when I think about those soldiers or airmen or marines or sailors who are out there fighting on my behalf and yet feel constrained, even now that Don't Ask Don't Tell is gone, because they are not able to commit themselves in a marriage, at a certain point I’ve just concluded that for me personally it is important for me to go ahead and affirm that I think same-sex couples should be able to get married."
Whew. That's a big moment.
Obama did go right ahead and counter that by saying that this is a personal decision, and that he still supports states' sovereignty in deciding the issue on their own.
Go ahead and watch the full interview, and then be as happy as your brain will allow, because this is kind of a big deal.