Hartford — Republican U.S. Senate hopeful Linda McMahon has lost her early lead on Chris Murphy and now trails the Democrat by 6 percentage points with less than two weeks to go in the race, according to a Quinnipiac University poll released Wednesday morning.

"This is a change from our prior two polls, when the candidates were locked in a virtual dead heat," poll director Douglas Schwartz said.

Yet the race remains fluid because 11 percent of Murphy voters and 14 percent of McMahon voters said they could change their minds before Nov. 6.

This latest opinion survey shows Murphy with the support of 49 percent of likely voters, compared to McMahon's 43 percent.

"It's déjà vu all over again in the Connecticut Senate race," Schwartz said. "As we hit the final stretch of the campaign, Linda McMahon is beginning to fade, as she did in her 2010 run against Richard Blumenthal."

Murphy, currently the state's 5th Congressional District representative, is extending his lead among women and older voters. Women back Murphy 52 percent to McMahon's 38 percent, and voters ages 55 and older prefer Murphy 51 percent to 42 percent for McMahon.

The independent university poll of 1,412 likely voters reports a 2.6 percent margin of error. It was done with live interviewers via land lines and cellphones.

Schwartz questioned whether McMahon, the wrestling entertainment magnate, has "hit her ceiling." Her favorability ratings have slid to 41 percent, down from 45 percent in an Oct. 4 Quinnipiac poll and 47 percent in the late August poll. Her unfavorable ratings are now up to 47 percent.

Voters with a favorable view of Murphy are at 39 percent, the same as his unfavorable rating. But 21 percent said they still don't know enough about him to have an opinion.

Poll criticized

McMahon's campaign on Wednesday was quick to criticize the latest poll's methodology. McMahon's own pollster, John McLaughlin, questioned whether the Quinnipiac team had "an agenda."

In a conference call with reporters, McLaughlin claimed the poll undersampled Republicans in the state by 6 percent. "For every point you take the Republicans down, you've just taken the Republican candidate down a point," he said.

He also faulted the use of random digit dialing rather than calling voters from a registration database. With random dialing, a pollster must take a chance that a respondent is telling the truth about his or her voter registration status.

McLaughlin questioned whether Quinnipiac's pollsters overstepped and editorialized the language in their news release, garnering unflattering headlines and radio bulletins for McMahon so close to Election Day.

Negative poll stories could affect the race's outcome by discouraging turnout, particularly from the unaffiliated and Democrats who are currently leaning toward voting for McMahon, he said. The Quinnipiac press release was titled "Murphy up as McMahon fades in Connecticut Senate race."

"You wonder if there's more of an agenda to this, where they're trying to produce an outcome or discourage the McMahon supporters," McLaughlin said.

The McMahon campaign's own tracking numbers show McMahon with a 1 point lead, he said.

'We stand by our results'

Schwartz defended Quinnipiac's methodology and impartiality.

"We stand by our results," he told reporters at the Capitol, noting the results of a 2010 poll released the day before that year's election. "If you look back in 2010, we had McMahon losing by 9. She ended up losing by 12, so I stand by our record for accuracy."

The current poll gives Democrats a 14-percentage-point representation advantage over Republicans. Exit polls in the 2008 race had Democrats with a 16-point advantage.

"We feel we have a good representative sample of the electorate," Schwartz said.

The previous Quinnipiac poll — conducted before McMahon's and Murphy's four debates — had McMahon in the lead by 1 percentage point. The late August poll, done after the primaries, showed McMahon ahead by 3 points.

"That's what's happening — she's fading," Schwartz said. "If you look at the numbers, her numbers in the horse race are going down."

Schwartz said his pollsters' random digit dialing approach has advantages over registration database calling because they sample more voters who own cellphones but not land lines, particularly younger people and minorities.

He also disputed the McMahon campaign's contention that bad publicity from poll numbers could affect the outcome on Election Day.

"It might affect fundraising, but it doesn't affect the voters," Schwartz said. "No research I've ever seen says a poll directly affects the way people are going to vote."

One academic colleague in the polling field agreed.

"I am not familiar with studies that show that news coverage of polls in any way suppresses turnout," said Tim Vercellotti, a political science professor and director of the Western New England University Polling Institute in Springfield, Mass.

"These are snapshots of what's going on now, not predictions of what's going to happen two weeks from now," Vercellotti added.

Likeability, job creation

The Quinnipiac poll also asked likely voters which candidate better understands their economic problems — 47 percent said Murphy and 42 percent McMahon. Also, 55 percent said McMahon would favor the wealthy over the middle class if elected, and 70 percent said Murphy would favor the middle class.

Asked which candidate "seems like the more friendly and likeable person," 45 percent replied Murphy and 40 percent said McMahon. But McMahon beat Murphy 48 percent to 38 percent on the question of who has better ideas for creating jobs.

The poll says 52 percent of likely voters believe McMahon's campaign is "intentionally misleading people." For Murphy's campaign, the misleading indicator was 47 percent. Two-thirds of respondents said the candidates' debates did not affect their views.

Outside the Senate race, the poll found that 55 percent of likely Connecticut voters prefer President Obama, compared to 36 percent favoring his Republican challenger, Mitt Romney.

The poll showed a small 2-point bump since August for Gov. Dannel P. Malloy's approval rating, now at 45 percent. Forty-one percent disapproved of Malloy's performance.

Retiring U.S. Sen. Joe Lieberman received a 53 percent approval rating. U.S. Sen. Richard Blumenthal's approval rating was 66 percent.

The Quinnipiac Polling Institute is undecided about conducting another Senate race poll before Election Day, Schwartz said.

j.reindl@theday.com