Collins likely needs about 1 in 10 Kamala Harris voters, nearly all of Donald Trump's and an electorate that doesn't tilt further toward Democrats.
The RealClearPolling average implies Collins is winning about 8% of Harris voters. Each scenario changes one thing from there.
Methodology: Bangor Daily News forecasts, based on Maine's certified 2020 and 2024 presidential results and those of the 2022 governor's race. Scenarios are calibrated to the RealClearPolling average as of Sept. 25 (Jackson 47.4%, Collins 46.4%), with undecided voters allocated proportionally. They assume Collins keeps 97% of Trump voters, a rate drawn from the New York Times/Siena/Portland Press Herald, UNH and UMass Lowell/YouGov polls, and that third-party presidential voters split evenly.