The AP is reporting this as a major coup--however, unlike Mike Long, chairman of the Conservative Party, the Independence party chairman did not actually pledge to oppose any GOP candidate that votes to redefine marriage:

The chairman of New York's Independence Party says he's personally supporting the legalization of gay marriage.

... The party representing 425,000 members is taking no official position on the issue. But MacKay tells The Associated Press Monday he's reminding lawmakers that the influential party's guiding principle is protecting civil rights.