By Sarah Dutton, Jennifer De Pinto, Anthony Salvanto, and Fred Backus

Ben Carson has surpassed Donald Trump and now narrowly leads the Republican field in the race for the nomination in the latest national CBS News/New York Times Poll.

Twenty-six percent of Republican primary voters back Carson, giving him a four-point edge over Trump (22 percent). Support for Carson has quadrupled since August.

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The rest of the Republican presidential candidates lag far behind in single digits. Marco Rubio is now in third place (eight percent), followed by Jeb Bush (seven percent) and Carly Fiorina (seven percent). All other candidates are at four percent or lower.

Carson has made gains across many key Republican groups. In a reversal from earlier this month, he is now ahead of Trump among women and is running neck and neck with him among men. Carson's support among evangelicals has risen and he now leads Trump by more than 20 points with this group.

Carson performs well among conservative Republicans and those who identify as Tea partiers. Trump does well with moderates and leads Carson among those without a college degree - although Trump had a larger advantage with non-college graduates earlier this month.

But the state of the race can change. Seven in 10 Republican primary voters say it is too early to say for sure that their mind is made up about which candidate they will support. This percentage is about what it was at a similar point in the Republican race four years ago.

While Carson may have moved to the top of the pack, Trump's supporters are more firm in their candidate choice than Carson's. More than half of Trump voters say their minds are made up about which candidate to back, compared to 19 percent who are currently backing Carson.

Paying Attention to the Campaign

Forty-three percent of registered voters are now paying a lot of attention to the campaign - similar to earlier this month - but up from 36 percent in September. More are paying a lot of attention now, compared to this point in time in the last two presidential election cycles.

Republican voters are more likely to be tuning into the campaign than Democrats.

This poll was conducted by telephone October 21-25, 2015 among a random sample of 1,289 adults nationwide, including 1,136 registered voters. Data collection was conducted on behalf of CBS News and The New York Times by SSRS of Media, PA. Phone numbers were dialed from samples of both standard land-line and cell phones.

The poll employed a random digit dial methodology. For the landline sample, a respondent was randomly selected from all adults in the household. For the cell sample, interviews were conducted with the person who answered the phone. Interviews were conducted in English and Spanish using live interviewers. The data have been weighted to reflect U.S. Census figures on demographic variables.

The error due to sampling for results based on the entire sample could be plus or minus four percentage points. The error for subgroups may be higher and is available by request. The margin of error includes the effects of standard weighting procedures which enlarge sampling error slightly.

An oversample of registered voters who are Republican was interviewed for a total of 512 interviews with Republican registered voters. The results were then weighted in proportion to the adult population. The margin of error for the Republican registered voters is 7 percentage points.

The margin of error for the sample of 575 Republican primary voters is 6 percentage points.

This poll release conforms to the Standards of Disclosure of the National Council on Public Polls.