WASHINGTON — A majority of Republican voters view only four of their party’s presidential contenders as potential general election winners, according to an Associated Press-GfK poll that reflects the sustained strength of the GOP’s outsider candidates.

Billionaire businessman Donald Trump is viewed as the strongest. Seven in 10 Republican and Republican-leaning registered voters say he could win in November 2016 if he captures his party’s nomination. Six in 10 say the same for retired neurosurgeon Ben Carson, who, like Trump, has tapped into the powerful wave of anti-establishment anger defining the early phases of the 2016 contest.

Former Florida Gov. Jeb Bush tops the field of experienced political leaders on the question of electability. Six in 10 Republicans say Bush could win the general election, followed by 54 percent who view Florida Sen. Marco Rubio as a potential winner. None of the other candidates is viewed as electable in a general election by more than half of Republican voters.