WASHINGTON — A new poll out Monday confirms that Ben Carson is topping Donald Trump in Iowa’s Republican caucuses — this time by 14 points. Both presidential candidates will be part of the large field of Republicans who will debate in Boulder Wednesday.

According to the Monmouth University poll released Monday, Carson is leading Trump 32 percent to 18 percent among likely Republican Iowa voters. In a Monmouth poll conducted in August, the two had been tied at 23 percent.

The poll confirms a shift in the state identified by two other polls in the past week. In the Des Moines Register/Bloomberg poll, Trump was up nine points, and Quinnipiac University showed him up eight percentage points.

Trump has begun to attack Carson on the trail as the retired neurosurgeon rises in the polls and challenges Trump’s front-runner status, though the mogul continues to lead nationally. Trump maintains that he only “counterpunches,” but Carson has not been making Trump a focal point of his campaigning in recent weeks.

The poll had good news for other GOP candidates, as well. Florida Sen. Marco Rubio has picked up 6 percentage points since August, to 10 percent. That’s good enough to tie for third place with Texas Sen. Ted Cruz. Jeb Bush has picked up three points to be in fifth place, at 8 percent. His favorability rates have also improved eight points since August.

On the other hand, Carly Fiorina’s post-debate bounce has seemingly ebbed, as she dropped from 10 percent in August to 5 percent in Monday’s poll.

Monmouth surveyed 400 likely Republican Iowa caucus-goers from Oct. 22-25 for the poll. which has a margin of error of plus or minus 4.9 percentage points.

Trump remains the Republican front-runner nationwide.