New York state Senator James Alesi, one of the four Senate Republicans who voted in favor of legalizing gay marriage in the state, announced Wednesday he will not seek reelection in the fall.

Alesi told the Daily News that he believes his vote weakened him politically.

He said the vote lost him the support of the local GOP and Conservative parties, both of which are backing his primary opponent.

“I've gotten a lot of support from Democrats and the gay community, but unfortunately they can't vote in a Republican primary,” Alesi told the paper.

Alesi, now in his eighth term, was the first Republican to announce his support for the measure.

He said he decided against seeking a 9th term out of fear it might hurt the Republican Party's chances of maintaining its razor-thin majority in the Senate.

“At some point, you have to really look at what is good for the party,” he said during a Capital Tonight interview. “What makes it easier to maintain the majority. And my not running is really the easiest way for the Senate Republicans to work with the Governor in the majority.”

The National Organization for Marriage (NOM), which strongly opposed passage of the marriage equality bill and was working against Alesi's reelection, wrote in a blog post: “Sen. Jim Alesi apparently saw the writing on the wall and realized his vote for SSM had already ended his political career.”