Who is Republican presidential candidate Ben Carson?

Republican presidential candidate Ben Carson on the campaign trail

Republican presidential candidate Ben Carson has risen up in the polls to nearly tie frontrunner Donald Trump.

Coverage of the 2016 race for the US presidency has been largely focused on Donald Trump, who has dominated the polls and the headlines with his larger-than-life persona and controversial views on immigration. But a very different candidate is slowly gaining on him.

On Tuesday, news broke that Dr Ben Carson, a retired neurosurgeon popular with evangelical voters, has just about tied Trump according to a new New York Times/CBS News poll. Carson strikes a dramatically different political pose, often noted for his calm demeanour and professorial speech style.

Carson's support leaped from 6% to 23% among likely Republican primary voters, whereas Trump increased his margin only slightly from 24% up to 27%.

However, both men have made much of their status as political outsiders.

"I'm not politically correct," Carson has said many times. "I am not a politician."

So who is he?

Early life

Ben Carson was born in 1951 in Detroit, Michigan. His mother raised him and his siblings after their father left the family when Carson was 8. He credits his mother, Sonya, with prioritizing his education even after he struggled with his grades.

Carson eventually went to Yale, where he met his wife Candy. Then he studied at The University of Michigan School of Medicine. He did his residency at Johns Hopkins Children's Center in Baltimore, Maryland, where he became the director of paediatric neurosurgery at just 33 years old. He pioneered techniques for operating on brain cancer and epilepsy.

Carson gained international fame in 1987 for performing the first successful surgery on twins conjoined at the head.

The pace of his work slowed when he was diagnosed and then successfully treated for prostate cancer in 2002.

Best-selling author and television fame

He has written a number of books including a 1990 memoir called Gifted Hands. In 2009, it became the basis for a movie on the television network TNT in which Carson was played by Cuba Gooding Jr.

He also spent much of his time speaking to classrooms of young students in Baltimore.

"I can't even count how many times I saw Ben Carson when I was a kid," writer Ta-Nehisi Coates once told to GQ magazine, "Any time anyone wanted to bring out any sort of inspirational figure for young black kids, especially young black boys, in Baltimore, you turned to Ben Carson."

The books also lay out Carson's strong religious convictions. He was raised a Seventh Day Adventist and these religious beliefs also inform many of his political views.

Political aspirations

Carson began drifting toward politics with the publication of his 2012 book, America the Beautiful: Rediscovering What Made This Nation Great, which was critical of the election of Barack Obama. He then rose to fame in the conservative political arena after giving a speech at a 2013 National Prayer Breakfast that was unexpectedly critical of Obama's health care plan.

The president was sitting just two chairs away, and Carson was exuberantly lauded for his gall by Rush Limbaugh and Sarah Palin. In a subsequent speech, he called Obamacare the "worst thing that has happened in this nation since slavery".

Later that same year, he retired as a surgeon.

A political action committee named "Draft Carson" began quietly amassing a $14m war chest, and in May 2015, Carson announced he would enter the presidential contest as a Republican. He has credited the draft movement as a major reason he jumped into politics.

Ben Carson announces he is running for president

Conservative and controversial views

Though his affect may differ from Trump's, Carson also has a history of controversial statements which have landed him in hot water.

While he concedes that gay marriage is now "the law of the land," at one point he told an interviewer that marriage should be between a man and a woman, and that "no group, be they gays, be they Nambla, be they people who believe in bestiality, it doesn't matter what they are, they don't get to change the definition". He also once said that homosexuality is a choice and said prison inmates were evidence of this. He subsequently apologised forboth comments.

Recently, he made headlines in California by denying that there is compelling evidence to support climate change. He identifies as pro-life and has supported a ban on abortions after 20 weeks. He says there is no contradiction between this and the fact that his past medical research was done using fetal tissue.