Susan Collins surpasses Mitch McConnell as the most unpopular senator in a new poll

Savannah Behrmann | USA TODAY

Show Caption Hide Caption Senator Susan Collins' disapproval rating is lowest among all senators The Maine senator's net approval rating has dropped 10 points since the end of September, leaving her with a 52 percent disapproval rating.

WASHINGTON – Republican Sen. Susan Collins has surpassed Senate Majority Leader Mitch McConnell as the most unpopular U.S. Senator, according to a new tracking poll.

The Maine Senator's net approval rating has dropped 10 points since the end of September, leaving her with a 52 percent disapproval rating, a quarterly Morning Consult tracking poll found.

The poll comes as Collins, one of the most moderate Senate Republicans on Capitol Hill, faces a tough reelection campaign for what would be her fifth term.

She was reelected in 2014 with nearly 70% of the vote, but Democrats see her as one of the more vulnerable Republican senators for 2020 where more GOP Senate seats are on the ballot than Democratic ones.

More: Let the impeachment trial commence

The race is expected to be Maine's most expensive ever, with nonpartisan ad tracking firm Advertising Analytics projecting $55 million in overall spending.

Her vote for Supreme Court Justice Brett Kavanaugh particularly rankled Democrats but shored up support from Republicans from her state in 2018. A crowdfunding campaign aimed at her defeat was generated in response to her Kavanagh vote and raised more than $4 million.

More: Rand Paul on Senate trial: 'I don’t think any Republicans are going to vote for impeachment'

“All five of the most vulnerable Senate Republicans head into the trial with voters in their states either souring on their job performance or with perceptions of the president threatening to pull them further down,” Morning Consult said in a press release on the poll.

Collins maintained her impartiality as the House impeached Trump, and is one of a few GOP Senators who hasn't been opposed to calling witnesses during the Senate trial.

She has criticized Democrats in the Senate as well as McConnell for predetermining their votes on the pending impeachment trial and has reiterated how she views her role as an impartial juror seriously.

She issued a statement Thursday saying that she would likely vote to hear new evidence and witnesses.

“While I need to hear the case argued and the questions answered, I tend to believe having additional information would be helpful. It is likely that I would support a motion to call witnesses at that point in the trial just as I did in 1999,” she said.

More: Lev Parnas, ex-Rudy Giuliani ally, wants to testify against Trump to win leniency. Sound familiar?

Kevin Kelly, spokesman for Collin's campaign, told USA TODAY that they "are confident" this poll "does not reflect reality, and Senator Collins remains focused on the job that Mainers elected her to do."

McConnell came in second as the least popular senator with a disapproval rating of 50 percent and an approval rating of 37 percent.

Morning Consult determined the Q4 2019 Senator Rankings by conducting 494,899 surveys with registered voters from October 1 through December 31, 2019. The margins of error vary by state and party.

Contributing: William Cummings