Has the Republican primary race begun to shift? For the first time in almost four months, Donald Trump no longer leads in the New York Times/CBS News national poll of GOP primary voters. Ben Carson has edged out ahead of Trump, 26/22, while every other candidate remains in single digits the day before the next prime-time debate:

Ben Carson has taken a narrow lead nationally in the Republican presidential campaign, dislodging Donald J. Trump from the top spot for the first time in months, according to a New York Times/CBS News survey released on Tuesday.

Mr. Carson, a retired neurosurgeon, is the choice of 26 percent of Republican primary voters, the poll found, while Mr. Trump now wins support from 22 percent, although the difference lies within the margin of sampling error.

The survey is the first time that Mr. Trump has not led all candidates since The Times and CBS News began measuring presidential preferences at the end of July.

No other candidate comes close to Mr. Carson and Mr. Trump. Senator Marco Rubio of Florida received 8 percent while former Gov. Jeb Bush of Florida and Carly Fiorina, the former Hewlett-Packard chief executive, are each the choice of 7 percent of Republican primary voters.

CBS’ Charlie Rose called this an “important shift” in the poll series:

How important is this shift? Well, it depends on how one sees the margin of error in a poll that has samples 575 GOP primary voters nationwide. CBS notes that the MOE is 6%, which makes this a virtual dead heat. It’s a subset of a larger poll, the full data for which will get released later when CBS and the Times wish to report on them. It’s also worth noting that while the Real Clear Politics poll tracking showed a decline for Trump (and for Carson) in early October in relation to a short-lived bump for Carly Fiorina, they both have seen their average polling numbers rise ever since.

Still, it represents a significant shift in this particular polling series. CBS on its own had Trump in the lead at the beginning of the month, 27/21. A month earlier, the previous CBS/NYT survey put Trump up four, 27/23. Combined with a slide for Trump in Iowa that has also benefited Carson, one could see a narrative build for a much-anticipated reckoning with reality for the 70-year-old real-estate tycoon … except, of course, that the RCP average clearly shows Trump picking up steam again in other polling.

Plus, with endorsements like this one, how can Trump be stopped?

“Let’s run America like a business, where no colors matter,” Tyson said. “Whoever can do the job, gets the job.”