A Platner superfan’s reluctance to support the Democrat now running against Senator Susan Collins reflects the party’s challenges navigating left-wing passions.

© Ryan David Brown for The New York Times

The spot casts the remark made at a debate by Senator Susan Collins’s Democratic opponent, Troy Jackson, as evidence of how he treats women.

© Charly Triballeau/Agence France-Presse — Getty Images

Three months after a jarring summer candidate switch, some Democrats in the state are worried about the enthusiasm for their nominee, Troy Jackson, who is in a close race.

© Cj Gunther/Reuters