Hillary Clinton holds a 10-point lead over Donald Trump among likely Colorado voters, according to a Quinnipiac University Swing State Poll released Wednesday.

When the two major-party nominees are tested against a pair of prominent third-party party candidates, Clinton’s lead in Colorado slips to 8 points.

It’s the sixth consecutive poll that shows Clinton comfortably ahead in Colorado, which has been considered a swing state in recent elections.

In the poll, which was conducted Aug. 9-16, Democrat Clinton beats Republican Trump with the support of 49 percent of likely Colorado voters to his 39 percent. In a four-way race, Clinton leads Trump 41-33 percent, with 16 percent for Libertarian nominee Gary Johnson and 7 percent for Green Party candidate Jill Stein.

Colorado voters appear to have highly unfavorable opinions about both Clinton and Trump, although that’s a contest Trump is winning by about 10 points.

Quinnipiac released presidential preference polls of likely voters in swing states Virginia and Iowa the same day. Clinton led by 12 points in Virginia but just 3 points in Iowa.

“The scary thing for Republicans in the Virginia and Colorado numbers is that they show a possible Hillary Clinton landslide in states that only eight years ago leaned GOP and before that had been GOP strongholds,” said Peter A. Brown, an assistant director of the poll.

President Barack Obama carried Colorado by 9 points in 2008 and by 5.5 points in 2012. But in the last five decades, only one other Democrat – Bill Clinton, when Ross Perot split the vote in 1992 – has managed to win the state’s electoral votes.

Brown attributed Trump’s struggle in Colorado, in part, to the state’s “burgeoning Hispanic population” and Trump’s incendiary remarks about Hispanics.

But Clinton is leading in nearly every group, according to Quinnipiac, including some that haven’t been won by Democratic presidential candidates in decades. She’s ahead 53-34 among women, 45-43 among men, 46-33 among independents, 64-29 among non-white voters and 58-33 among white voters with college degrees. Clinton is also winning in every age group. Trump leads among Republicans, white voters without college degrees and voters who say they live in a military household.

“Colorado and Virginia are important swing states. Faced with these deficits in those states, Trump’s situation is similar to the poker player who must draw to an inside straight flush,” Brown added.

Neither candidate is very popular, with 56 percent of likely voters holding an unfavorable opinion of Clinton and 40 percent thinking highly of her. Trump is even further upside down, with 66 percent disliking him and only 29 percent expressing a favorable opinion.

Potential first gentleman Bill Clinton has a 51-43 percent favorability rating in Colorado. Obama scored a 54-42 percent favorability rating, while first lady Michelle Obama rates best, with 59-28 percent favorability. A slim majority of the state’s voters don’t have an opinion about Trump’s wife, Melania, though those who do are evenly split, with 24 percent favorable and 25 percent unfavorable.

Clinton’s voters are more likely to be voting for her, as opposed to against Trump or simply backing the party’s nominee. Thirty-seven percent say the main reason for their vote is support for Clinton, while 48 percent say they oppose Trump, and 13 percent say they vote for the Democrat. Among Trump’s voters, 22 percent say they support the billionaire, 62 percent say they oppose Clinton, and 10 percent say they back the Republican.

In an NBC News/Wall Street Journal/Marist poll released last week, Clinton led Trump among Colorado voters 46-32. In the four other publicly released polls conducted since Clinton and Trump secured their parties’ nominations, Clinton led by an average of 9.5 points.

“Will Colorado be a mountain just too high for city slicker Donald Trump to climb? The state labeled the next California, swinging from red to blue, has given Hillary Clinton a double- digit cushion,” said Tim Malloy, assistant director of the Quinnipiac University Poll, in a statement. “Colorado likely voters say Trump is likely not their guy.”

The poll sampled 830 likely Colorado voters and has a reported margin of error of plus-or-minus 3.4 percentage points.

– ernest@coloradostatesman.com