I just spoke with Arline Isaacson, who was a central figure in the battle for same-sex marriage here in Massachusetts. Isaacson says that even yesterday morning, when word was spreading that Obama was going to speak on the issue, she didn't believe he would come out fully in favor of the right for same-sex couples to wed.
"I give him a lot of credit for this," Isaacson said. "This was a genuinely bold, brave, gutsy move for him to make."
"It was so profoundly moving to hear the President of the United States -- the leader of the free world -- saying those words unequivocally," she said. "His pronouncement yesterday was a sea change; not in the law, but politically and culturally the earth moved yesterday."
She also predicted that, as we've seen happen in Massachusetts, there will come a time before long when it is essentially impossible for a Democrat to rise to high elected office while opposing same-sex marriage.
"Anyone now who wants to be viewed as a true supporter of GLBT equality [while opposing same-sex marriage] can't hide behind the President," Isaacson said.