Rob Portman, a Republican senator, now supports gay marriage:
I have come to believe that if two people are prepared to make a lifetime commitment to love and care for each other in good times and in bad, the government shouldn’t deny them the opportunity to get married.
Indeed, Portman has not only accepted his son but publicly changed his views on gay rights at potentially significant political cost. He has often been discussed as a possible Republican presidential contender; this will surely make it impossible for him to be nominated for president or vice president in 2016, and he will probably face an anti-gay-marriage challenger when he seeks re-election in three years. Portman has to know that what he did today was the opposite of politically expedient, and he did it anyway.
I think Barro is right that it comes with great risk and he did it because he truly believes it’s the right thing to do (after all, it would be easier to not touch the issue at all), but I also think that the environment within the GOP is slowly becoming more amenable toward supporting gay marriage, and he may think that supporting it now rather than later will be an advantage.
In any case, it’s a huge step for the party that a prominent Republican elected official has publicly declared their support for gay marriage. Jon Huntsman did the same just recently, but Portman has a much higher stature in the party. A snowball is forming.