My partner is foreign born and we want to marry in a state where same-sex marriage is legal. Will doing so enable me to sponsor him or her for a “green card”?

Yes, most families will now be able to obtain a green card. With the end of DOMA, LGBT families will be treated the same under immigration law as different-sex immigrant families. 

Immigration law is complicated and there will still be barriers for some couples, but the systemic discrimination that prevented our families from receiving the same respect under the law as others has ended. Green card applications will no longer be denied solely because a couple is lesbian or gay.