Mike Michaud (D), US Rep. for ME-02 and Maine gubernatorial candidate has come out. Since Maine legalized gay marriage by popular vote, I doubt this will affect him very much.
He's in a tight three-way race, so any votes this may cost him would be bad. But it's far enough away from the election that hopefully it will be old news by then.
Interesting. I usually don't put much stock in what commenters say but their points about the differences between the congressional districts in Maine seem legit. I'm very interested to see how this unfolds.