NOM's Communications Director Thomas Peters was interviewed by Politico to respond to the news that Sen. Rob Portman has chosen to abandon his view on marriage:

A spokesman for the National Organization for Marriage on Friday slammed Sen. Rob Portman, who has announced that he now supports same-sex marriage, reversing his long-held opposition to the issue.

“What Mr. Portman is doing is shrinking the size of the GOP tent,” charged Thomas Peters, a spokesman for the socially conservative NOM, in an interview with POLITICO. “I think it will have huge consequences if he chooses to run again.”

Peters, speaking with POLITICO at CPAC, said that opposition to same-sex marriage unites religious and social conservatives on both sides of the aisle, and also resonates with demographics that include parts of the Latino community.

...Peters charged that if Portman has presidential ambitions of his own, the new stance on gay marriage will torpedo those hopes.

“As far as Sen. Portman and presidential chances, I think he can say goodbye to those,” Peters said. He added that while it’s too early to say what impact this policy shift could have on a 2016 re-election bid for Senate, “we can say that every time a Republican has come out for gay marriage, he ignites the grassroots.”

Ryan Anderson has also responded at Heritage's blog.