Famed neurosurgeon Ben Carson confirmed Sunday he’s entering the Republican race for president, furthering an unlikely political journey that began when a 2013 speech at the National Prayer Breakfast made him an instant hero with conservatives.

Carson, who rose from urban poverty to become a world-renowned pediatric neurosurgeon, will make a formal announcement Monday morning in his hometown of Detroit after visiting a high school there that bears his name. In an interview that aired Sunday on West Palm Beach CBS affiliate WPEC-Channel 12, he said he’s entering the race for the White House.

Carson, 63, never has run for office and only joined the Republican Party in November after being registered with the obscure Independence Party of Florida. But he’s hoping voters are ready for an unconventional candidate.

“I’m not 100 percent sure that politics as usual is going to save us,” Carson told Channel 12.

Carson became a national celebrity and an inspirational figure for black youth — but not a political figure — as director of pediatric neurosurgery at Johns Hopkins University in Baltimore. He led a pioneering 1987 operation that successfully separated infant German twins who were joined at the cranium. He became a regular on the motivational speech circuit and was the subject of a 2009 movie starring Cuba Gooding Jr.

Carson retired in 2013 and moved to a golf course community in West Palm Beach, Fla.

At the National Prayer Breakfast in 2013, with President Barack Obama seated a few feet away on the dais, the soft-spoken Carson criticized liberal political correctness, the national debt, the complexities of the tax code and an education system that he said has “dumbed things down” and enabled America to drift from its founding principles. He argued for a flat income tax and criticized Obama’s signature health care law by calling for health care savings accounts.

Conservatives soon began calling for Carson to run for president. He finished third in a 2014 straw poll of potential Republican candidates at the Conservative Political Action Conference, trailing only Sens. Rand Paul of Kentucky and Ted Cruz of Texas. He also placed near the top of some national polls of Republican voters early this year.

Carson formed a presidential exploratory committee in March and reported that it raised $2.1 million in its first four weeks, mostly from small donors.

But Carson’s momentum has slowed since he formed the exploratory committee. Cruz, Paul and Florida Sen. Marco Rubio have launched presidential campaigns since then and moved ahead of him in most polls of Republican voters.

Carson also was sidetracked by controversy in March after he said in a CNN interview that homosexuality is a choice “because a lot of people who go into prison go into prison straight and when they come out they’re gay.”

He soon apologized, saying “my choice of language does not reflect fully my heart on gay issues. I do not pretend to know how every individual came to their sexual orientation. I regret that my words to express that concept were hurtful and divisive.”

In his Sunday Channel 12 interview, Carson said the experience taught him not to “wander off into those extraneous areas that can be exploited. I have learned that.”