The Quinnipiac poll gives Murphy 49 percent support to McMahon's 43. That's an improvement for Murphy from the last Quinnipiac poll, conducted in early October, which showed the race a statistical dead heat, with McMahon 1 point ahead of Murphy.

Murphy's strong lead is in part due to McMahon's erosion of support among women — he now leads her among women by 14 percent, whereas in early October he had only a 6-percentage-point lead over McMahon with women.

Still, 11 percent of Murphy voters and 14 percent of McMahon voters say they could change their mind in the coming weeks, meaning these last 14 days could be pivotal. Most other polls of the race have given Murphy a slight lead over McMahon, but the race remains close: Of the four polls released this week, including the Quinnipiac poll, one showed the race at a dead heat and another gave Murphy just a 1-percentage-point lead.

However, as director of the Quinnipiac University poll Douglas Schwartz points out, history might be repeating itself in McMahon's second bid for Senate.

"It's deja vu all over again in the Connecticut Senate race. As we hit the final stretch of the campaign, Linda McMahon is beginning to fade, as she did in her 2010 run against Richard BlumenthalRichard BlumenthalSenate panel approves Mattis for Defense secretary Senate Dems urge Sessions to abstain from voting on Trump’s Cabinet picks Takata will plead guilty, pay B in faulty airbag probe MORE," he said in a release.

Schwartz wondered if McMahon might be hitting her polling ceiling at this point — she won only 43 percent of the vote in 2010, the same amount of support she has in the new poll.

In that race, as in this one, she ran close to Blumenthal, but ended up losing on Election Day in part due to a 20-point deficit among women, a problem she seems to be seeing again today.

Though McMahon's made efforts to course-correct somewhat this time around, it seems the entry of outside groups — the Democratic Senatorial Campaign Committee has spent nearly $2.5 million on the race so far — has evened out McMahon's spending advantage and done some damage to her own appeal.

Her favorability is now under water, down from early October, when 45 percent of voters viewed her favorably to 41 percent who viewed her unfavorably. Voters are evenly split on Murphy.

McMahon's campaign manager Corry Bliss, however, dismissed the results of the new poll, citing the two other polls that indicated the race is effectively tied.

"If it weren’t so close, Congressman Murphy might not be lying to the people of Connecticut about his record of voting for higher taxes for the middle class, voting against funding to build submarines in Groton," he said in a statement.

The survey was conducted among 1,412 likely voters from Oct. 19-22 and has a margin of error of plus or minus 2.6 percentage points.