Kerrey was a major Freedom Fighter. He even voted against the Defense of Marriage Act in 1996.
Kerrey hasn't run for senate since then though. I'm sure his opponet will use that the play into the fears of Nebraskans who voted for the state DOMA. 70% voted for it and it was written in a way that made sure to ban anything that resembled a civil union(it was ruled unconstitutional by a court but a higher court overturned their ruling unfortunately).
It might not matter because it seems like Nebraskans don't like to talk about politics and would vote for Kerrey just because he's a war veteran and they voted for him before.