One day before the second Republican presidential debate, Ben Carson is pulling nearly even with GOP front-runner Donald Trump , according to a new New York Times/CBS News poll .

The retired neurosurgeon has jumped to 23 percent in the poll to be released Tuesday evening. That's a significant bump up from an August CBS poll that showed the candidate at just 6 percent. Trump continues to lead the field with 27 percent, up 3 percentage points from the previous poll.

While Carson has gained, Jeb Bush and Scott Walker have experienced the greatest loss of support in the poll. Bush has fallen from 13 percent to 6 percent, and Walker has dropped from 10 percent to just 2 percent.

Businesswoman Carly Fiorina, who didn't even register in the last poll, has risen to 4 percent.

The HuffPost Pollster National Republican Primary chart , which aggregates all available polls, finds Trump sitting at 34 percent while showing a more modest gain for Carson, who sits at 19 percent.

The NYT/CBS News poll also found that only 37 percent of Republican voters have decided which candidate they will vote for; the majority, 63 percent, have yet to make up their minds.

These findings underscore that few Americans are paying attention this early on in the race, making primary polls less predictive of the final outcome.

The NYT/CBS News poll surveyed national Republican primary voters Sept. 9 through Sept. 13 and has a margin of error of 6 points.