Ben Carson, pictured here at the Eagle Council forum in St. Louis, has the potential to pull ahead of Donald Trump following the upcoming CNN G.O.P. debate. PHOTOGRAPH BY BILL GREENBLATT / UPI / LANDOV

This is getting interesting. On Tuesday, the day before the second televised G.O.P. debate, a new poll, carried out for the New York Times and CBS News, showed Ben Carson, the former neurosurgeon, gaining strongly on Donald Trump among Republican voters. This is the latest in a series of surveys that has shown Carson moving up, but the previous surveys still had Trump ahead by double digits. In this one, Trump’s lead was down to just four points, which isn’t even statistically significant. Twenty-seven per cent of likely G.O.P. voters said that they would support Trump, and twenty-three per cent said that they would support Carson.

Yes, it is just one poll, and the usual caveats about sampling error and outliers apply. But this was the first national survey carried out since Trump made his offensive remarks about Carly Fiorina’s appearance, and it suggests that they may have damaged him and helped Carson. In stark contrast to Trump, Carson is unfailingly courteous, and he is very popular among Christian evangelicals.

The poll raises the stakes for tomorrow night’s Republican debate, which will be shown on CNN. Assuming that Carson emerges from the debate without making any big mistakes, he could well enjoy another lift, which would raise an intriguing possibility: Will establishment Republicans, in the interests of defeating Trump, whom they regard as a dangerous interloper, start to rally behind Carson—another political neophyte, but one who seems less eager to challenge traditional G.O.P. nostrums than Trump is?

At this stage, anyway, the polling data suggests that Carson is the only electorally viable alternative to Trump in the G.O.P. primary. In the new survey, as in a number of previous ones, all of the candidates except Trump and Carson scored in the single figures. Jeb Bush, Mike Huckabee, and Marco Rubio each got six per cent. Ted Cruz got five per cent. Fiorina got four per cent. The rest of the pack got three per cent or less.

Backers of more orthodox Republican politicians will no doubt be hoping that these candidates do well in Wednesday’s debate and subsequently pick themselves up off the floor. But how long can the party hierarchy and its financial backers afford to wait? With Trump parading around the country, saying C.E.O. pay levels are disgraceful and promising to abolish some tax breaks enjoyed by the rich, some of his fellow plutocrats are already eager to take him down. On Tuesday, the Club for Growth, a right-wing pressure group that has received funding from a number of conservative billionaires, announced that it was launching an anti-Trump advertising campaign in Iowa and other states. “We’ll continue doing it until people realize that Donald Trump is not an economic conservative,” the organization’s president, David M. McIntosh, said at a press conference in Washington.

As the old saying goes, though, you can’t beat something with nothing, and, right now, Carson looks like he might be the something that worried Republicans need. A world-renowned surgeon who was brought up in Detroit by his mother, after his parents divorced, Carson has an inspirational life story to relate. A supporter of a balanced-budget amendment, a skeptic about most government programs, and a harsh critic of Obamacare (last year, he said it has done more damage to the United States than the 9/11 attacks), he is singing a tune that conservatives want to hear. On the basis of what we’ve seen so far, he may well have the calmness and self-confidence to stand up to Trump’s jibes without being rattled. Last week, after Trump questioned Carson’s energy level and called him just an “O.K. doctor” —a laughably inaccurate description—Carson responded gracefully.

For Carson, a lot depends on Wednesday night’s debate. CNN has been promoting the event as “Round two of a heavyweight bout,” and much of the attention will be focussed on how Trump and Fiorina interact, following Trump’s offensive remarks about Fiorina’s appearance. But Carson, who was largely overlooked at last month’s Fox News debate, will also be a big part of the story. If he holds his own, or does better than that, it would confirm his position as the main rival to Trump.

Until now, the Republican establishment, for want of a better strategy, has been largely waiting for the Trump phenomenon to blow over. Recently, some of the candidates, Jeb Bush included, have started to criticize Trump, but that hasn’t done them much good, either. In a year when much of the Republican electorate appears to have soured on all politicians, only Carson has made much of a dent on Trump’s lead. If you were a mega-rich Republican, or a Karl Rove type, why wouldn’t you take that as a cue to throw some serious money and organizational might in the direction of Carson’s campaign, which, until now, has largely relied on small donations? If nothing else, it could serve as an insurance policy.

It has been widely reported that many Republican bigwigs and strategists have serious doubts about Carson’s political skills, and his ability to withstand all of the attention and craziness that comes with being a serious contender. That’s understandable. He’s a doctor, not a politician, and he has made some gaffes in the past, such as suggesting that the prevalence of homosexuality in prisons shows that being gay is a choice. (He subsequently apologized for this remark.)

Most of the Republican super-donors and super PACs have to date directed their favors elsewhere. However, on Sunday, the Times reported that Carson was starting to attract some larger donations. He has also added a number of fund-raisers to his schedule. That could be just the beginning. If Carson keeps doing what he has been doing, Trump does the same, and the establishment candidates continue to founder, it might not be long before Carson receives a call from Washington saying that some fellows in expensive-looking suits would like to meet with him.