A post-election poll of unaffiliated voters released Thursday has a sobering message for the Colorado GOP: President Donald Trump’s unpopularity may have accelerated the party’s growing disadvantage in state politics by sinking its chances with independents.

The phone poll, conducted by a Republican firm Nov. 7-9, confirmed that unaffiliated voters — whose participation surged to historic levels for a midterm election — broke with tradition by favoring Democrats by huge margins on Nov. 6. Unaffiliated voters who turn out in midterms in Colorado tend to break for Republicans, while leaning left in presidential elections.

Unlike previous Democratic electoral routs, the poll suggests, it’s less likely Republicans will be in a position to bounce back in two years, when Trump is up for re-election.

“What is still the most important voting bloc is all of the unaffiliated voters,” said David Flaherty, the founder and CEO of Louisville-based Magellan Strategies. “And the bottom line is that boy oh boy, they did not like what Republicans were offering up. And boy oh boy, they do not like this president. … It could not have been a darker day.”

The poll of 500 Colorado unaffiliated voters who participated in the election found a 34 percentage-point advantage within that group for Democratic gubernatorial candidate Jared Polis over Republican Walker Stapleton. Among all voters, Polis’ winning margin was 10.5 percentage points, according to the Secretary of State’s Office.

At the same time, the poll says that unaffiliated voters who cast ballots have a dismal view of the Republican Party, with only 25 percent of the sample reporting a favorable impression of the GOP.

Flaherty said respondents’ recurring responses to an open-ended question about their impressions of the GOP — including hostility toward immigrants, perceived racism and antipathy toward the working class — suggested Trump was a prevailing factor in that distaste.

In last week’s election, Democrats notched across-the-board statewide victories that exceeded the party’s national performance, including a sweep of state constitutional offices. Democrats also retook the state Senate majority and expanded their state House majority.

Unaffiliated voters played an outsized role, Flaherty said, as both their turnout (878,360) and that of registered Democrats (849,610) each outpaced Republican ballot returns (813,644) for the first time ever in a midterm election in Colorado.

More poll findings

Here are among the most notable findings from the poll, which has a margin of error of plus or minus 4.38 percentage points:

Trump’s job approval rating among unaffiliated voters was 31 percent, while 62 percent disapproved. Nearly half of respondents said Trump influenced their vote, and among those, the president harmed Republicans’ appeal nearly 3-to-1.

Fifteen percent of women in the survey said they considered candidates from both major parties equally, compared to 36 percent of unaffiliated female voters who said so in a 2016 poll. Flaherty said this was a symptom of increased polarization.

Polis, a congressman, won the votes of 59 percent of respondents, compared to 25 percent for Stapleton, the outgoing state treasurer. Four percent supported other candidates, and 12 percent refused to say who they voted for. Though women supported Polis more strongly than men, he won majority support among both groups.

Polis heavily outspent Stapleton by largely funding his own campaign, though outside groups filled some of the gap by running a steady diet of attack ads against Polis. The poll found Polis won the messaging war among unaffiliated voters, while some respondents mentioned perceptions that Stapleton was dishonest or a liar — suggesting, Flaherty said, a potential backfiring of the attack ads against Polis.

The fact that Polis is gay was cited by a handful of respondents as a negative factor in their vote, but it was just as likely to be cited positively by others as a reason they supported Polis.

In the last decade, Democrats have overtaken Republicans slightly in voter registration, while the bloc of unaffiliated voters has outpaced both. Current registration stands at about 29 percent Republican, 30 percent Democrat and 39 percent unaffiliated — compared to nearly equal one-third shares for each group in 2008.

“Time will tell if the 2018 election was an acceleration of the Republican Party’s waning ability to win statewide elections in Colorado, or a sobering period of clarity that sparked a new direction for the GOP,” Flaherty wrote in a polling memo.

“There is an abundance of survey data and voter trends to support our claims, and all Colorado Republicans should be worried.”

Document: Polling memo and topline results