奥巴马和罗姆尼的激烈竞争

President Obama’s decision to support same-sex marriage in the United States could have an impact on what is expected to be a close presidential election in November. But most experts believe the president’s fate is still tied to the domestic economy.

At a New York fundraiser featuring singer Ricky Martin, President Obama's supporters applauded his recent announcement in support of same-sex marriage.

"We have never gone wrong when we expanded rights and responsibilities to everybody," said President Obama. "That doesn’t weaken families. That strengthens families.”

Public opinion polls show Americans divided on the issue of same-sex marriage.

The presumptive Republican nominee, Mitt Romney, spoke out in favor of traditional marriage at Liberty University, a Christian-oriented university in Virginia.

“Marriage is a relationship between one man and one woman," he said.

Gallup pollster Frank Newport says the issue could help Romney rally conservative voters.

“So I think it could turn out to be a plus for Romney in that it will motivate a lot of his supporters to perhaps be more energetic than they were otherwise," he said. "Whether it will change people’s minds who are kind of in the middle is a little difficult to tell at this point.”

Democrats believe the president’s change of heart on gay marriage will help him in November.

But Republican House Speaker John Boehner says the economy remains the critical issue.

“And the president and the Democrats can talk about all this all they want," he said. "But the fact is the American people are focused on our economy and they are asking the question, where are the jobs?”

An improving economy is crucial to the president’s re-election chances, says Brookings analyst Thomas Mann.

“Wages are stagnant, unemployment is high and people are pretty discouraged about the state of the economy," Mann said. "And each time it appears we are really coming out of it, then we have a setback again.”

Obama supporters are running a new ad critical of Mitt Romney’s business career.

“Bain Capital always made money. If we lost, they made money," stated the ad.

The Romney campaign is firing back with a video of its own defending his record.

“When others shied away, Mitt Romney’s private sector leadership team stepped in," said the Romney ad.

With less than six months before Election Day, neither candidate appears to have a big advantage, says pollster Frank Newport.

“You put it all together and my conclusion looking at it is that it is a very close race at this point," he said. "In fact when we asked people who would you vote for if the election were today, voters in America, basically it is tied at about 46 [percent] to 46.”

And a race that experts say will likely remain close right up until November.