(ABC News)

Rep. Barney Frank, D-Mass., the first openly gay member of Congress, said this morning on "This Week" that he "expected" President Obama to support same-sex marriage and dismissed the idea that he would suffer a political backlash for his decision.

"I expected the president to be supporting same-sex marriage, because, frankly, of the absence of any good reason against it," said Frank. "I can't think there are many people who said, 'OK, well, I'm going to vote for Obama even though he said that the Defense of Marriage Act is unconstitutional and he said gay people can serve in the military.  But if he says marriage, that goes too far.'  I literally don't think anybody's vote was changed by this one way or the other."

Rep. Marsha Blackburn, R-Tenn., said that the likely Republican nominee for president, Mitt Romney, would focus on jobs this election season after I asked her if Mitt Romney would follow Rick Santorum's advice and use  President Obama's shift in support of gay marriage as a "weapon."

"I think that what you're going to see Mitt Romney do is put the focus on jobs and the economy," she said. "I think that you can go back and look at Supreme Court cases, you can look at the institution of marriage, and you know that Mitt Romney, who has always fought for traditional marriage, is going to continue to do this."

President Obama declared his support for same-sex marriage earlier this week during an interview with ABC News' Robin Roberts.

"I've just concluded that for me personally it is important for me to go ahead and affirm that I think same sex couples should be able to get married," Obama said.