He was lying to maintain greater electoral appeal. There's evidence of Obama personally supporting same-sex marriage in 1996 lol.

Then DOMA was repealed, the Matthew Shepard Act passed, Don't Ask, Don't Tell ended, federal benefits expanded to same-sex partners, hospitals required visitations of same-sex partners, Stonewall made a national monument, the Trevor Project was funded, and Obergefell happened.

We should always remember from our leftist betters that posturing, rhetoric, and moral purity are more important than winning power and enacting material change.