Republican presidential candidate Ben Carson speaks to reporters during a news conference Nov. 6, 2015, in Palm Beach Gardens, Florida.
Republican presidential candidate Ben Carson speaks to reporters during a news conference Nov. 6, 2015, in Palm Beach Gardens, Florida.

U.S. Republican presidential candidate Ben Carson said Sunday he is receiving more scrutiny than others who have run for president because of the threat he poses to “the secular progressive movement in this country.”

Carson has soared to the top of the 2016 Republican presidential heap, where he remains with real estate mogul Donald Trump, with an inspiring story about his rise from a difficult childhood in Detroit, Michigan, to a successful career as a neurosurgeon.

But in recent days, media outlets have been reviewing several stories Carson describes in his autobiography, Gifted Hands, and have found that many of the claims are difficult to verify.

The Wall Street Journal reported that the class "Perceptions 301," mentioned in the book, did not exist while Carson was a student at Yale University, despite his claims that he was the only student not to walk out after being told he had to retake an exam. That piece also questioned his recollections about high school, including a claim that he protected white students during a race riot.

Politico questioned the veracity of Carson's oft-repeated claim that he was offered a "full scholarship" to the U.S. Military Academy at West Point, which does not offer scholarships because the cost of attendance for those accepted into the school is free.

Ben Carson watches as Donald Trump takes the stage
FILE - Ben Carson watches as his main rival, real estate mogul Donald Trump, takes the stage during a Republican presidential debate at the University of Colorado, Oct. 28, 2015.

Carson told ABC's This Week television news show on Sunday that the West Point website uses the word "scholarship," so that he was not wrong to use this word in the past when describing overtures from military officials who told him when he was young that they could get him a "full scholarship" to the academy.

Also Sunday, Carson repeated his stance that the level of scrutiny to which he is being subjected has never been applied to others who have sought the presidency, including Barack Obama.

"I have always said that I expect to be vetted, but being vetted and what is going on with me - 'You said this 30 years ago, you said this 20 years ago, this didn’t exist' ... I have not seen that with anyone else," he said during an interview on NBC's Meet the Press.  "It's time to really move on," he said.

But his main rival Trump did not heed that suggestion, instead raising questions about Carson's accounts of his past on four different Sunday talk shows.  Trump called Carson's tales "strange" and "weird," in a conversation with ABC's This Week.

"He's going to have to explain a lot of things away," Trump told NBC's Meet the Press.