Clinton has 49% support to Trump's 37%, with Libertarian Gary Johnson at 9%, according to the poll of 750 likely voters. The poll was conducted Friday through Monday and released Tuesday evening, meaning many of those polled were surveyed before the Orlando terrorist attack.
Particularly damaging for Trump: 55% of those surveyed said they would never vote for him, compared to 43% who said they'd never back Clinton.
It's a much larger lead than Clinton held in national polls conducted in May and early June, prior to Trump's accusation that the federal judge in the Trump University lawsuit is biased because his parents were born in Mexico and Trump is advocating a U.S.-Mexico border wall.
The poll also asked voters to what degree recent Trump and Clinton controversies "bother" them.
Fifty-five percent of those surveyed said they were very bothered by Trump's remarks, which drew rebukes from top Republicans such as House Speaker Paul Ryan, who called Trump's remarks "the textbook definition of a racist comment."
Seventy-two percent of voters said Trump's comments about the judge bother them. Another 71% say the Trump University lawsuits bother them, and 67% said they're bothered that Trump hasn't released his tax returns.
Also damaging: His attacks on women such as Heidi Cruz and Carly Fiorina bother 81% of those surveyed; 66% said they are bothered by his attacks on Mexicans as "bringing drugs, they're bringing crime, they're rapists," and his plans to deport 11 million undocumented immigrants. The same number, 66%, say they're bothered by his proposal to ban Muslims from entering the United States.
Clinton faces damaging problems, too. Seventy percent said they're bothered by her use of a private email server, while 73% said her paid speeches to Wall Street banks bother them, and 72% say the Clinton Foundation's acceptance of foreign countries' donations during her tenure as secretary of state bothers them.
"Clinton has a number of advantages in this poll, in addition to her lead," pollster J. Ann Selzer, who ran the poll, told Bloomberg. "Her supporters are more enthusiastic than Trump's and more voters overall see her becoming a more appealing candidate than say that for Trump."
The survey found that the mass shooting in Orlando did little to affect voters' preference in the presidential race.
However, Trump bested Clinton, 45% to 41%, when voters were asked which candidate they'd have the most confidence in if a similar attack occurred, once that question was added Sunday and Monday night.
Meanwhile, 50% said Trump would better combat terrorist threats at home and abroad, while 45% chose Clinton on that question.
The poll's margin of error on those issues is plus or minus 4.9 percentage points, compared to 3.6 percentage points for the bulk of the survey.