The number of contributors in 2012 who gave in support of gay marriage dwarfed donors who opposed it.

According to a report released Wednesday by the Human Rights Campaign (HRC), the nation's largest gay rights advocate, supporters outnumbered opponents by a 13-1 margin.

Approximately 133,000 contributors gave to campaigns in the four states where the issue was on the ballot. Campaigns working against marriage equality attracted an estimated 10,500 donors, HRC reported.

Maine on November 6 became the first state to legalize gay nuptials at the ballot box, while Minnesota became the first to reject an effort to ban such unions. Washington state and Maryland voters upheld marriage laws approved by lawmakers.

Proponents raised more than $34 million in the four states, mostly from small donors.

Opponents relied heavily on the contributions of the National Organization for Marriage (NOM), the Catholic Church and its affiliate the Knights of Columbus, which combined contributed nearly two-thirds ($8 million) of the $12 million raised.

(Related: First gay couples marry in Washington.)