Sara Gideon, Democratic candidate for U.S. Senate, speaks to Bates College students Friday in Lewiston. Credit: Robert F. Bukaty / AP

Ranked-choice voting could prove the deciding factor in Tuesday’s U.S. Senate race, as a new poll gives Democrat Sara Gideon a plurality advantage over incumbent Republican Susan Collins.

The poll, conducted by Emerson College and its last before Election Day, showed 48 percent of voters backed Gideon, compared with 42 percent for Collins, who is seeking her fifth term. The independents in the race — Lisa Savage of Solon and Max Linn of Bar Harbor — picked up 5 percent and 1 percent support, respectively.

Another 4 percent of voters were undecided, while 1 percent said they planned to vote for someone else.

If no candidate picks up a majority of votes during the first round of counting Tuesday, the race will head into an instant runoff under Maine’s ranked-choice voting law. The Emerson College poll is the latest to suggest that could advantage Gideon, the Maine House speaker.

Under ranked-choice voting, Gideon would pick up 61 percent of Savage’s voters, compared with 14 percent going to Collins. The remainder opted to rank no candidate as their second choice, according to the poll.

Another poll, conducted by SurveyUSA for the electoral reform group FairVote and shared exclusively with the Bangor Daily News last week, showed voters were more likely to rank a Democrat as their second choice and Gideon making slight gains during an instant runoff, finishing 51 percent to Collins’ 49 percent.

Those results mirror a Colby College poll released last Wednesday, with more than half of Savage voters breaking for Gideon on the second count.

The Emerson College poll also showed Democrat Joe Biden with a wide lead over Republican President Donald Trump, who is seeking his second term in office.

The poll gave Biden an 11-point lead statewide over the incumbent (54 percent to 43 percent), but the size of the lead varied considerably when broken down to Maine’s two congressional Districts. In the more liberal 1st District, Biden has a 19-point advantage over Trump (58 percent to 39 percent), while Biden has a more modest 3-point lead (50 percent to 47 percent) in the more conservative 2nd District.

The president won the heavily rural 2nd District by 10 percentage points in a historic split of Maine’s Electoral College votes in 2016. It has also been the subject of unprecedented campaigning late in the election cycle. Trump visited a Levant orchard on Oct. 25, days after sending Vice President Mike Pence to a rally in Hermon and soon followed with a second appearance in Greater Bangor from his son Donald Trump Jr. Biden’s wife, Jill Biden, visited the district for the second time on Oct. 27.

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