(CNN) - Donald Trump did not back down Tuesday from his questioning of President Barack Obama's birthplace, instead arguing heatedly with CNN's Wolf Blitzer that "a lot of people do not think it was an authentic certificate," though he declined to offer names of experts who agree with him.
The issue of Obama's birth - litigated in the 2008 presidential campaign, then settled when the Obama White House released the longform version of the certificate in April 2011 - is being brought to the fore in no small part by Trump, who is also set to fundraise alongside presumptive Republican presidential nominee Mitt Romney Tuesday evening.
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On CNN's "The Situation Room" Tuesday, Trump maintained that Obama's birthplace is a matter of opinion, rather than fact.
"Everybody's entitled to your opinion," he said. "You know my opinion and you know his opinion and that's fine. We're entitled - as he said yesterday in the airplane - we're all entitled to our opinions and he's entitled to have his opinion. I don't happen to share that opinion, it's wonderful."
Blitzer presented Trump with newspaper announcements of Obama's birth from 1961.
Trump interrupted, "Can you stop defending Obama?"
"Donald, you're beginning to sound a little ridiculous, I have to tell you," Blitzer replied.
"You are, Wolf," Trump fired back. "Let me tell you something, I think you sound ridiculous."
Trump then alleged that the practice of filing U.S. birth announcements for an overseas birth was commonplace, though he offered no evidence.
"Many people put those announcements in because they wanted to get the benefits of being so-called born in this country," Trump said. "Many people did it."
Obama's longform birth certificate showed he was born in Hawaii on August 4, 1961 and was acknowledged as authentic by state officials. Natural born American citizenship is one of the Constitutional requirements for the presidency.
"Is it the most important thing?" Trump asked in an interview earlier on Tuesday. "In a way it is. You're not allowed to be the president if you're not born in the country."
Trump finds himself at odds with GOP presidential candidate Mitt Romney, whose spokeswoman pointed out in an email statement that "Governor Romney has said repeatedly that he believes President Obama was born in the United States."
But Romney made no effort to distance himself from the comments, even when presented with the opportunity by reporters on Monday.
"You know, I don't agree with all the people who support me and my guess is they don't all agree with everything I believe in," Romney said when asked about the issue. "But I need to get 50.1% or more and I'm appreciative to have the help of a lot of good people."
Trump said he has not spoken about the birther issue with Romney
"I haven't talked to Mitt Romney about it," he said. "What I speak to Mitt Romney about is jobs. What I speak to Mitt Romney about is China, because he's got a great view on China and how they're taking our jobs and taking our product and manipulating their currency so it makes it almost impossible for our companies to compete."
Trump spoke by phone with Blitzer in the interview from Las Vegas, where he and Romney will fundraise with former GOP presidential candidate Newt Gingrich.
Obama's campaign released a web video on Tuesday that said the 2008 GOP nominee "John McCain stood up to the voices of extremism in his party… Why won't Mitt Romney do the same?" In the video, McCain is seen addressing a woman who called Obama an "Arab," saying, "He's a decent family man, citizen that I just happen to have disagreements with."
The president's deputy campaign manager suggested Romney's alliance with Trump in light of the tycoon's statements calls into question how he would serve as president.
"Mitt Romney's continued embrace of Donald Trump and refusal to condemn his disgraceful conspiracy theories demonstrates his complete lack of moral leadership," Stephanie Cutter said in a Tuesday afternoon statement. "If Mitt Romney lacks the backbone to stand up to a charlatan like Donald Trump because he's so concerned about lining his campaign's pockets, what does that say about the kind of President he would be?"
White House Press Secretary Jay Carney said Tuesday the White House was forced to address the issue last year, "but not because we chose to, but because it was such a ridiculous distraction from the important business that we should be doing here that the president is committed to doing and Congress should be doing to help the economy grow and help it create jobs."
"We can revisit that but I think the American people are pretty fed up with this kind of nonsense," he said.
As evidence of his claims, Trump pointed to a biographical note published in the 1990s by Obama's literary agent, which said Obama was born in Kenya.
The literary agent recently apologized for the mistake.
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President Obama hates the subject....Really you think? Hey Trump I think after 4+ years anyone would hate this subject...Give it a rest already you are beginning to sound like you've gone off your meds!
I can't understand why the news media feels compelled to spend so much time talking about Donald Trump. It only gives validity (which is undeserved) to the man. Trump spews pure garbage from his mouth. There has to be more worthwhile stories to cover than this.
Where is the outrage that Obama's mentor was a rabid anti-American and many of his associates similarly anti-American, even terrorists. And Obama took $1 million from Bill Maher, a notorious purveyor of hate speech.
wolf is in democrats pocket. trump made him look bad
What a ridiculous piece of stupidity. Trump should be in lunatic asylum. The man is ill. Please end this. Is there a doctor in th4e house?
There you go, girl (or are you a guy?). I mean, please, I am an independent but these republicans are way, way, above anyone's logical sense...unless you're just a republican sheep, you would believe anything an anti-obama would say just because...I guess, before 1961, a fortune teller told Barry's mom that her son would become the first black president, so therefore, she should prep a fake US birth certificate before flying to Kenya to join the harem...I guess, pilgrimage to your husband's country is a must to deliver your first born...then fly back again to the mother's country of origin (which in this case is the US) before anyone would notice that the mother was not really on US soil during delivery...and so the tale goes on...
Lets just say for argument sake that Obama is not a US citizen. Wouldn't that be the most embarassing for the US. Imagine the press relaease to the rest of the world – We are sorry to announce that we just found out that the person who ws our president for the last 4 years was elected by mistake and .....
Would be the joke of the century, if not ever.
McCain's birthplace no in question, but Pres. O that is fair play? Mr. Trump you are a racist clown?
Trump wins this one hands down. Blitzer showed what a clueless, brainless, deer in the headlights idiot he is with his last place finish on Jeopardy.
"You shall be kbown by the company you keep" Seems like a relevant quote.
I don't believe that Donald Trump is self-made billionaire. That's a matter of fact, not opinion.
can you say, publicity hungry money grubbing loud mouth
Trump fired back. "Let me tell you something, I think you sound ridiculous."
Did Donald Trump, of all people, really just say that about someone else? Maybe he should've paid for an independent poll before the interview: Who's more ridiculous, Wolf Blitzer or Donald Trump?
You know I'm getting sick and tired of this issue, just leave it alone.
Whenever you think Trump couldn't be more of an inflated phoney buffoon than he already is, he opens his mouth.
Donald Trump should stick to commenting on what he knows......which is nothing
How do we know Trump is a natural born citizen? Let's see his long form. Even if he did show it, that doesn't mean it is authentic. He could have easily paid someone to falsify his birth certificate. See how easy it is to become a birther and a conspiracy theorist.
Donald Trump stupid rich guy and so Romney
You're not allowed to be President if you're not born in this country? Then why was John McCain running? Trump is such a loud mouthed bully.
That's right! Obamer was born in Kenya and needs to be deported!
While the birth issue is important, can any of you dems provide a list of Obama achievements? Why do you stand up for him? What do you expect from the next 4 years?
Let's discuss this in a logical & civilized way.
If you listen to hateful and stupid people, it rubs off. Donald Trump wants to Trump somebody. Hello Donald Trump, you don’t measure up to President Obama, no matter what you say or do! Donald Trump is a bad hair stupid bigot who needs attention! Donald Trump is a street rat! You put the rat in a penthouse rather than a sewer, give it a bath and a plane, but the rat is still a nasty hungry rat! Wolf, Trump puts his pants on the same way you put your on, one leg at a time. He trumped you with the mess! He wants to be vice President!
I fail to see the upside of Donald Trump continuing down this crazy path. How does it benefit him? For someone who is supposed to be "highly intelligent", he argues like an eight year old on the playground.
Why do media clowns give Trump any airtime Trump is a big-mouthed, arrogant bag of wind!
I hope Trump has many more fundraisers for Romney where both are on stage together. This will continue to prove to intelligent Americans what a loser Romney is. He does not have the backbone to tell Trump that he is a fool for his birther statements.