Poll: Donald Trump and Ben Carson increase lead over Jeb Bush

A new poll by the Wall Street Journal/NBC News finds Donald Trump has increased his lead over the Republican field, with 25 percent support among GOP primary voters, an increase of four percentage points from a poll taken in late September.

Ben Carson follows close behind Trump with 22 percent, and Marco Rubio takes up third with 13 percent, up two percentage points from September. He is the only other GOP candidate in double digits.

Jeb Bush, meanwhile, attracted only eight percent support, trailing Ted Cruz, who has nine percent. In June, Bush was the top choice, with 22 percent support. Carly Fiorina is close behind Bush, with seven percent support.

The poll also found that now, more Republican primary voters say they can't see themselves supporting Bush - 44 percent - than Trump, at 36 percent. This is a sizable change from June, when 74 percent could not imagine supporting Trump. Seventy-four percent said they could see supporting Carson, and 65 percent said they could see themselves supporting Rubio.

Full results of the new Journal/NBC News poll, which surveyed 1,000 adults, will be released on Tuesday. Included in the survey were 400 Republicans who say they plan to vote in the primaries. The margin of error for that group was plus or minus 4.9 percentage points.