Washington - Billionaire Donald Trump extended his lead yet again atop the Republican presidential field, with front-running Democrat Hillary Clinton slipping and Vice President Joe Biden faring better than her against Republicans, poll results revealed on Thursday.
Trump, the combative real estate mogul, leads the 16 other Republican candidates with 27% support among registered voters nationwide, up from 20% in a similar July 30 survey by Quinnipiac University.
Thursday's lead marks the widest margin for any Republican so far in the election cycle, the survey said.
Retired neurosurgeon Ben Carson placed second with 13%, former Florida governor Jeb Bush earned eight percent, Senator Ted Cruz came in fourth with seven percent, and Senator Marco Rubio fifth with six percent.
"Other GOP hopefuls seem to disappear. Trump proves you don't have to be loved to be the leader," said Quinnipiac poll assistant director Tim Malloy.
Trump's abrasive style, including his open and caustic criticism of rivals, has led some observers to say he does not have the temperament to be president, but he has dominated the race essentially since he declared his candidacy in June.
On the Democratic side, Clinton's support has shrunk, to 44% now compared with 55% on July 30, while her main rival Senator Bernie Sanders is polling at his highest level, 22%.
Match-ups
Biden, who is not a declared candidate but is mulling jumping into the race, earned 17% in the poll. Significantly, Biden "has the best appeal in general election match-ups against top Republicans," Malloy said.
Biden beats Trump by nine points, Bush by five points, and Rubio by three points.
Clinton beats them too but by smaller numbers: four points, two points and one point respectively.
Despite Trump's Republican lead, he has the highest negative favourability numbers in the field, at 35% to 55%. Bush is underwater as well, at 33-41, while Clinton's negative 39-51 matches her worst favourability rating ever.
Biden's favourability rating was positive, at 46-41, while Rubio's was 42-28 and Sanders 32-28.
Trump and Clinton are also seen as the least honest and trustworthy of the field.