Sharon and Jim Schear,of Annapolis, right, thank Dr. Ben Carson, left, after he completed brain surgery operation.

When President George W. Bush bestowed the Medal of Freedom, the nation's highest civilian award, on Ben Carson in 2008 he lauded him as a scholar, healer, and leader. He recounted Carson's up-from-poverty journey that led him to become one of the most celebrated and inspiring men in the country for his work in medicine. His books were best-sellers, lining the bookshelves of many homes, including my childhood home in small-town South Carolina.

His story and message was for everyone.

Carson's White House citation read:

Dr. Benjamin Carson is a pioneer in pediatric neurosurgery, and his life is a testament to the power of education, hard work, and faith. His groundbreaking contributions to medicine provide hope for people suffering neurological disorders, and his tireless outreach to America’s youth underscores the importance of academic achievement and humanitarian service. The United States honors Benjamin Carson for his skill, his vision, and his dedication to motivating others to strive for excellence.

A year later a movie was made about his life. In 2013 Carson retired as the head of the Division of Pediatric Neurosurgery at Johns Hopkins.

But somewhere along the way Carson got the political bug. And his career has taken an unexpected detour ever since. On his way out of practicing medicine, an uproar around comments he made about same sex marriage forced him to withdraw as commencement speaker at his university.

By some measures it has gone quite well since then for the surgeon-turned-politico.  A recent CNN/ORC poll of Republicans showed Carson coming in second only to Mitt Romney as the preferred choice for the 2016 GOP nomination. His political standing led CNN to call him a "political phenomenon" and we've written about how he could make a mark in the 2016 field.

But, while he is likely to galvanize some parts of the social conservative segment of his party, he has almost no chance of winning.

That's one reason he should probably consider not running. But there is a better argument sitting out there. A Michael Jordan comparison is in order. Remember when Michael Jordan, the most celebrated basketball player ever, decided to retire the first time and take up baseball? Hopefully not.  It was a disaster, proving in embarrassing fashion that transcendent skill in one arena does not so easily transfer to another.

Take note, Dr. Carson.

(Conservatives will say this column is all about the mainstream media lining up against black conservatives. Political reporters and pundits supposedly gang up on black conservatives because they are rare and upend the idea that all blacks are  -- and should be?-- Democrats, the argument goes.  This is nonsense. Colin Powell and Condi Rice, anyone? They have both been reported on as plausible candidates.  Ben Carson isn't in their league.  Not even close.)

Carson is doing something odd, which has nothing to do with being a black Republican. Rather than trading up, as can happen with presidential candidates who run credible races, he is trading down. Way down.

He is now a staple of conservative cable news, yet another talking head on the already-crowded political landscape. Carson has traded a stature that had afforded him a much earned authority on issues like education and health care for a role as a conservative hero to a relatively narrow wing of the GOP.  He is now playing small ball on an overcrowded stage -- and he's not even doing that very well at the moment.

This week included several low lights. On conservative Christian radio he blamed feminism for what happened in Ferguson, Missouri.

I think a lot of it really got started in the '60s with the "me" generation. "What’s in it for me?" I hate to say it, but a lot of it had to do with the women’s lib movement. You know, "I’ve been taking care of my family, I’ve been doing that, what about me?" You know, it really should be about us.

And then there was his turn on CNN, where he sat for an almost 30-minute interview.   His latest fight against alleged political corectness -- a favorite Carson hobby horse -- was over comparing the present day United States to Nazi Germany. His response to Wolf Blitzer, who reminded him that he was talking about "the slaughter of six million Jews by the Nazis, the devastation that erupted in Europe and around the world," was this:

Again, you are just focusing on the words ‘Nazi Germany’ and completely missing the point … and that’s the problem right now. That’s what PCism is all about. You may not say this word, regardless of what your point is. Because if you say that word, I go into a tizzy. We can do better than that. When I was a child, and when you were a child, they used to say, ‘Sticks and stones break my bones, words will never hurt me.’ What ever happened to that? We need to get to the point where we can look beyond the word and look for the meaning.

One of the world's most renowned surgeons, with a biography that is incredibly compelling, fought over his right to compare the contemporary United States to Nazi Germany. On national television.

Yes, it's his right to do that, and some (very, very, very few people probably) might say it is a worthy one. But it is a throwaway fight, fit for cable news but utterly beneath someone like Carson.

Look, if Carson runs (and he probably will) he will cement his role as a conservative firebrand, appealing to "teavangelicals."  He might get a talk show.  Maybe another book deal, higher speaking fees, more hits on cable news.  All good things sure, but ultimately really ordinary and not at all in short supply.

Carson had been that rare, above-it-all figure, someone who could command a broad audience with his remarkable story and unparalleled surgical skill. In joining the political fray so actively (and fervently) the Ben Carson brand is changed -- and diminished.