GOP poll: Trump ahead, Carson down, Rubio and Cruz gaining

Donald Trump still leads the Republican presidential field, a new poll says, while Ben Carson appears to be fading and Marco Rubio and Ted Cruz seem to be moving up.

Trump pulls 27% of Republican voters, according to the Quinnipiac University National Poll released Wednesday, followed by Rubio at 17%; Carson and Cruz are tied for third at 16%.

In the same poll last month, Trump barely led Carson, 24%-23%.

"It doesn't seem to matter what he says or who he offends -- whether the facts are contested or the 'political correctness' is challenged -- Donald Trump seems to be wearing Kevlar," said Tim Malloy, assistant director of the Quinnipiac University Poll.

He added that Carson, a retired neurosurgeon, "now needs some CPR."

No other Republican candidate cracked double digits in the survey; Jeb Bush was in fifth place at 5%.

In the Democratic presidential race, Hillary Clinton continued to lead big, besting Bernie Sanders by 60% to 30%.