Washington (CNN)A new poll shows Donald Trump still holds a strong lead over his challengers in the 2016 Republican primary field.
Pew poll: Donald Trump holds commanding lead
The Pew Research Center poll, released Friday, shows Trump with 25% support from likely Republican voters nationwide. Retired neurosurgeon Ben Carson grabbed 16% support, Florida Sen. Marco Rubio and former Hewlett-Packard CEO Carly Fiorina got 8% each and Texas Sen. Ted Cruz garnered 6% support.
Meanwhile, Jeb Bush -- at one time the front-runner in national polls himself -- garnered 4% support.
The poll, conducted between Sept. 22 and Sept. 27, asked possible voters an open-ended question of who they would support for the Republican nomination. Unlike some other surveys, pollsters did not provide a list of names.
There was strong name recognition for Trump, but 25% of respondents said they did not know who they would vote for at this point -- just four months away from the first primary.
Trump has been riding high in the polls for months now, but Carson and Fiorina have climbing their way up, too. Trump told CNBC's John Harwood Thursday that if he suddenly begins plummeting in the polls he will drop out of the race.
"Well, I'm not a masochist," Trump said Thursday. "Right now I'm leading every poll, and in most cases big. That's good. If that changed, if I was like some of these people at 1% and 2%, there's no reason to continue forward. If I fell behind badly, I would certainly get out."
The survey comes from 496 Republican potential primary voters and had a margin of error of plus or minus 5 percentage points.