During an appearance on The Daily Show, President Barack Obama reminded host Jon Stewart that his Republican rival, former Massachusetts Governor Mitt Romney, opposes gay marriage.

Unlike Obama, who in May endorsed gay nuptials, Romney has said he supports a constitutional amendment defining marriage as a heterosexual union.

“Four years ago I said I would end the war in Iraq, we did, said I would pass health care reforms, make sure people don't go bankrupt when they get sick, we have, said we would refocus our attention on al-Qaeda, we have, made sure that we saved an auto industry that was on the brink of collapse, we've done that. So we have a very strong story to tell. Whether it's on social issues like Don't Ask, Don't Tell, or economic issues that matter for middle class families.”

“I do think that part of the president's job is not only moving forward on things that will work but also preventing things that won't work.”

“I think you want a president in the Oval Office who's going to say, 'No we're not going to amend our Constitution for the first time to restrict rights for gay and lesbian couples,” he said to loud applause from the audience.

(Watch the entire segment at Hulu.com.)