Washington, November 14 (RHC)-- Jeb Bush, who was the early frontrunner for the Republican nomination for U.S. president, has plummeted to the low single digits in a latest national poll. The Quinnipiac University survey found Bush taking only 4 percent support, down from 10 percent in September.

Meanwhile, Donald Trump and Ben Carson continued to lead the crowded Republican field, with the New York billionaire gaining 24 percent support, followed by the retired neurosurgeon at 23 percent.

In a hypothetical general-election matchup, however, Carson defeated Democratic front-runner Hillary Clinton. Trump and Carson have been trading first and second place in recent national polls, but Carson has been on the rise.

Senator Marco Rubio is in third place at 14 percent, up 5 points since September. And Senator Ted Cruz is in fourth place with taking 13 percent support. In hypothetical head-to-head match-ups, Republicans have beaten Clinton, the leading Democratic candidate for president.

Carson has a 50 percent to 40 percent lead over Clinton. And over more, Carson has a narrow lead over Clinton among female voters, while Clinton leads Carson among Black men by at least 20 points.

Clinton also trails behind Rubio, Chris Christie and even Ted Cruz in head-to-head match-ups. However, Clinton leads Trump 46 percent to 43 percent in such scenario.

Democratic candidate Bernie Sanders also performed as badly as Clinton did in all of those match-ups against Republicans.