Publicly questioning whether President Barack Obama is a natural born citizen of the United States will hurt Republican candidates in the 2012 elections, according to New York City Mayor Michael Bloomberg.

"Look, anybody can run for president if you're 35 and an American citizen and born here," Bloomberg said on Fox News Sunday. "The president was born here. This birther issue is more than one person. There are a lot of roots that have glommed on to this."

Many so-called "birthers" believe there is persuasive evidence that Obama was born in Kenya in 1961 and that his birth certificate was faked in order to make him eligible for the Presidency.

Reality TV star Donald Trump recently brought the issue back into the media spotlight when he first revealed he had some doubts that Obama was a U.S. citizen during an interview with ABC News' Ashleigh Banfield in March. Trump has been courting the media's attention by questioning Obama's eligibility for president ever since.

"I think the Republicans are making a terrible mistake in making this a big issue," Bloomberg continued. "We have immigration. We have the deficit. We have the economy. Those are the things that the public cares about... If the Republican Party doesn't start addressing that, they will lose and they deserve to."

"Here is an opportunity for both parties and for the president to take a look and say look, guys, we have been sitting around, we've been talking back and forth," he added. "We have been fighting. It's good theater, but the country can no longer afford this. The American public is smart enough to understand that. Let's focus on the main issues."

The Democratic Governors Association is trying to raise money off of the "birthers" with a fundraising pitch that mocks recent attempts in Arizona, Louisiana and other states to force presidential candidates to produce their birth certificates.