Well, let's see how this plays out.
It seems like she wanted WHY she's a yes made clear. She is up for reelection, iirc.
And she has a 100% chance at winning that election even if she voted no. Her spot is cemented because the people in Maine actually like her as one of their Senators. The other one was Olympia Snow but she got fed up with the *** and retired, which Angus King then ran as Independent and won. King being a sort of local legend.
Olympia is called a RINO by the rest because she votes for what she believes is best for Mainers and not by what the Republicans wants. She's a fiscal conservative but a social moderate. That's the whole reason she was considered a wild card vote, the Republicans have zero leverage on her. She won her last election with a 68.4% against her Democrat opponents 31.6%. Before that it was her 61.5% vs the Democrats 38.5%. She could sleep through her next election and still win as it's not a question of if she wins but by how much she'll win. Which is what made the whole "if you vote yes we're raising all this money to fight you" line by liberals hilarious.
Also explains why she spent so long reading the FBI report, she likely read the whole damn thing and then reread sections before making up her mind.