Donald Trump – the New York (alleged) billionaire who may or may not seek the 2012 Republican Presidential nomination – has made yet another high-profile enemy over his accusations that President Barack Obama may not have been born in the U.S.

Speaking on NBC while attending his Tribeca Film Festival, legendary actor Robert DeNiro slammed Trump for espousing the birther movement.

I won't mention names, but certain people in the news the last couple weeks, just, what are they doing? De Niro said, according to Movieline.

It’s crazy. They’re making statements about people that they don’t even back up. Go get the facts before you start saying things about people. It’s like a big hustle. It’s like being a car salesman. Don’t go out there and say things unless you can back them up. How dare you? That’s awful to do. To just go out and speak and say these terrible things? Unless you just wanna get over and get the job. It’s crazy.

DeNiro later admitted he was referring directly to Trump.

In response, Trump questioned DeNiro’s intelligence.

“Well, [DeNiro’s] not the brightest bulb in the planet,” Trump told the Fox News Network.

“I have been watching him over the years and I like his acting but in terms of when I watch him doing interviews and various other things, we are not dealing with Albert Einstein. He can say what he wants, but the fact is [Obama] has not revealed his birth certificate. A lot of people agree with me. With all that I do, what I do best is China, jobs, OPEC. That’s what I do best, that is going to be my strength.

Trump further added: Recently I did a Tea Party event and we had a tremendous crowd. They love this issue. There are so many people that really want him to provide his birth certificate. Now you have states going out and saying, 'In order to run for office, you have to be able to provide a birth certificate.' There's a big lot of things going on with respect to the birth certificate. Why is [Obama] spending millions of dollars to fight this issue, instead of just providing his birth certificate? There are so many different elements here and I will say, it's a very frightening thing for this country.

Last week, top television comedian Jerry Seinfeld cancelled out of appearing at a Trump-connected charity show because he was “uncomfortable” with Trump’s repeated attacks on Obama.

New York Mayor Michael Bloomberg and Arizona Senator John McCain have also blasted Trump over the birther claims.

However, despite all the backlash he has received, Trump has at least one significant political bigwig on his side.

According to media reports, Queens Republican County Chairman Phil Ragusa wants Trump to speak at his organization’s next fundraiser.

If you look at upstate New York, all the manufacturing jobs in upstate New York are gone and I think someone like Trump would want to get those jobs back here in the United States, Ragusa told WNYC.

So we know him and to me he is a type of guy who gets things done and that's what we need.