Sen. Jim Alesi apparently saw the writing on the wall and realized his vote for SSM had already ended his political career:
During an exclusive interview on Capital Tonight, Republican Sen. Jim Alesi made a surprise announcement: He has decided not to seek re-election in his Rochester-area district.
Alesi sparked controversy when he became the first Republican to publicly support same sex marriage last year.
... Conservatives and many Republicans in his district have been eyeing Alesi’s seat. And Democrats in the district also felt he was vulnerable and could be defeated.
When the senator sat down with Liz Benjamin tonight he said he thought an intra party battle could cost the Republicans the majority. And he decided to step aside for the good of the conference and the party because he has lost support from local GOP committees and was widely expected to face a primary challenge from Assemblyman Sean Hanna.
...He said he’s unlikely to leave public life entirely, and joked that with his liberal views on social issues, he could perhaps move to Manhattan and run for office where he’d be more likely to get elected. -- Capital Tonight