Soft-spoken GOP presidential candidate Ben Carson on Friday lashed out at the news media for recent stories about his long-ago past, saying they are bias and amount to a “witch hunt.”

Carson, a retired pediatric neurosurgeon, has indeed faced intense media scrutiny over the past couple of weeks as he moves to the front of some national primary polls.

Over the past several days, Politico published a story questioning whether Carson, a first-time candidate, receiving a scholarship offer from the U.S. Military Academy at West Point.

And CNN reported finding no support for Carson's oft-repeated claim that he tried to stab a close friend as a teenager. Citing privacy concerns, his campaign has refused to name the person involved.

"I think what … these kinds of things show, is there is a desperation on behalf of some to try to find a way to tarnish me," Carson said Friday night during a news conference outside West Palm Beach, Fla.

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He also said such efforts will only strengthen him among supporters, who “understand this is a witch hunt.”

In an intense exchange with reporters during the news conference, Carson argued President Obama didn't receive the same level of scrutiny in his 2008 White House bid.

“In fact, I remember just the opposite,” he said.

Carson cited Obama’s relationships with Frank Marshall Davis, who had ties to the Communist Party, and Bill Ayers, a college professor who in the 1970s led the radical left group the Weather Underground.

He also asked reporters why they haven’t tried to unseal Obama’s under-graduate records.

“Why are you guys not interested in why his records are sealed?” Carson asked.

Still, Republican presidential candidate Donald Trump told NBC's "Meet the Press" Sunday that Carson would have to "explain a lot of things away" about his West Point and youth recollections.

Carson has developed a passionate following based in part on his inspirational personal story and devotion to Christian values. The only African-American in the Republican 2016 class, he grew up in inner-city Detroit and often speaks about his childhood brushes with violence and poverty.

Following the Politico story that was published Friday, the Carson campaign sought to clarify the candidate’s story about his interest in attending West Point in his breakout book, "Gifted Hands," in which he outlines his participation with the Reserve Officers' Training Corps, commonly known as ROTC, while in high school.

"I was offered a full scholarship to West Point," Carson wrote in the 1996 book. "I didn't refuse the scholarship outright, but I let them know that a military career wasn't where I saw myself going. As overjoyed as I felt to be offered such a scholarship, I wasn't really tempted."

Campaign spokesman Doug Watts said Carson was "the top ROTC student in the city of Detroit" and "was introduced to folks from West Point by his ROTC supervisors."

"They told him they could help him get an appointment based on his grades and performance in ROTC. He considered it, but in the end did not seek admission," Watts said.

Students who are granted admission to West Point are not awarded scholarships. Instead, they are said to earn appointments to the military academy, which come with tuition, room and board and expenses paid, in exchange for five years of service in the Army after graduation.

A West Point spokesman on Friday said the academy "cannot confirm whether anyone during that time period was nominated to West Point if they chose not to pursue completion of the application process."

At the Friday news conference, Carson said, "It was an offer to me. It was specifically made." He said he could not recall specifically who made the offer. "It's almost 50 years ago. I bet you don't remember all the people you talked to 50 years ago," he said.

Pressed further by reporters, Carson said: "What about the West Point thing is false? What is false about it?" Asking if he had made a mistake in recounting the story, he said, "I don't think so. I think it is perfectly clear. I think there are people who want to make it into a mistake. I'm not going to say it is a mistake, so forget about it."

Hours earlier, Carson had told Fox News in an interview, "I guess it could have been more clarified. I told it as I understood it."

In a post Wednesday on his Facebook page, Carson wrote that "every signer of the Declaration of Independence had no elected office experience." About half had been elected members of colonial assemblies, and Watts acknowledged the error to The Washington Post.

On another topic, Carson has said the great pyramids of Egypt were built by the biblical figure Joseph to store grain, although the accepted science says that they were tombs for pharaohs.

The Associated Press contributed to this report.