After finishing 4th in Iowa and 8th in New Hampshire (behind Carly Fiorina, who completely missed the last two debates), Ben Carson is currently polling 5th (out of 6 remaining candidates) in South Carolina. He further appears to be doing less campaigning in South Carolina than his rivals and has purchased less media.
In short, there is not at all an obvious path for him to actually win or do well in South Carolina, and there's not a ton of evidence that he is really even trying. However, just by being on the ballot, he helps Donald Trump by splitting at least some portion of the vote that would otherwise go to other candidates, and so it sounds like that's exactly what he plans to do. Here he is on Morning Joe this morning sounding like a man who is basically planning to run interference for as long as he can:
Mika: So, what is your strategy moving forward in South Carolina, perhaps even to make that message (NB - "that message," in context is "Ted Cruz cheated!!") very clear to voters who take values very seriously there?
Carson: Well, South Carolina is the kind of place where I love to come. You know, I've understand (sic) the people here, I think they understand me, and I think we're going to do extraordinarily well here. It's a matter of really getting out in front of enough audiences so that they get a chance to see me and hear me as opposed to the way that I have been characterized by many in the media.
Mika: Alright, Steve Kornacki?
Kornacki: Doctor, if you don't prevail or if you don't do well in South Carolina - you didn't do well in New Hampshire, you were a bit off the lead in Iowa - if you're not able to get a breakthrough in South Carolina, is that a moment you might reassess the future of your campaign?
Carson: I reassess the future of the campaign every day. So of course I will continue to do that. You know, I had no expectation of doing well in New Hampshire, and you know, a lot of people who spent millions of dollars there and many, many weeks there didn't do that well either (NB - those candidates have dropped out of the race). Uh, I was able to foresee that, and you have to pick your battles.
Well, a couple things here. First, Ben Carson has been on 8 nationally televised debates now, talking to the voters using his own words. The idea that there is a humongous cache of voters in South Carolina who have somehow not seen Ben Carson for themselves just absolutely beggars the imagination.
Second, if the problem with Ben Carson is that he hasn't been able to overcome the way the media unfairly portrays him, and that he needs to be able to talk to voters directly without media interference, then that is proof positive (if more was needed) that he would be a disaster in the general election. The Republican nominee will always face a hostile media that is in the tank for the Democratic nominee, and if he or she is unable to overcome that and win votes anyway, then he or she is doomed.
Third, and most importantly, Carson shows no signs of setting a goalpost at any time for his candidacy that he must meet. Santorum, Huckabee and Paul set down a marker that if they did not do well in Iowa, their campaigns would not be viable. Christie, Fiorina, Bush and Kasich did the same in New Hampshire. One presumes that is because those candidates were in this to win the actual nomination, and when they realized that could not happen, they gracefully stepped aside.
The fact that Carson refuses to set any sort of equivalent marker for himself, in spite of a total lack of success in either Iowa or New Hampshire, indicates that he is running much more of a Ron Paul 2008 campaign, whose design was never to win but rather to build a massive email/mailing list that could be sold and/or used for gain later. Heck, maybe I'm wrong, but I get the sense that after Carson finishes fifth in South Carolina, he'll be invited back on Morning Joe to explain why Nevada's going to be a great state for him, and then after that, he'll be on to talk about all the Super Tuesday states he expects to win.