New Hampshire State Representative Jim Splaine won't seek re-election., the Foster's Daily Democrat reported.

Splaine was the chief backer behind a bill that recognized gay and lesbian couples with civil unions in 2007 and last year's gay marriage law.

The Democrat has a varied history in the New Hampshire Legislature, serving in both chambers at various times. He was the youngest House member when he was elected in 1968.

In announcing his decision not to run again, the 62-year-old politician cited passage of the gay marriage law as one of his proudest moments.

“We expanded civil rights by passing marriage equality,” he said. “I think that was a very important thing to do for a lot of people. It was an important message for our young people – that people should be treated with not only tolerance, but acceptance.”

New Hampshire's gay marriage law took effect on January 1. Governor John Lynch signed the bill into law less than an hour after lawmakers gave final approval. With not a single favorable Republican vote in sight, Democrats in the Senate were left to do all the heavy lifting.

Opponents continue to push for repeal of gay marriage in the state. The National Organization for Marriage (NOM), the nation's most vociferous opponent of gay marriage, has targeted Lynch's re-election campaign because he signed the bill into law.

Splaine is one of four openly gay men elected to the House. Also serving are Dana Hilliard, David Pierce and Ed Butler.