A Republican super PAC aimed at supporting pro-gay marriage GOP candidates raised a strong $2.75 million in the first quarter of 2014.

The three-month haul for American Unity PAC is by far the biggest so far for the super PAC, which was around for the 2012 election but had relatively little funding. The committee raised about the same amount in all of 2012 and pulled in just $260,000 in 2013.

The super PAC was boosted early this year by $1.75 million in donations from GOP donor Paul Singer, who has been among the most vocal and well-funded proponents of gay marriage in the GOP.

Another $1 million came from billionaire Massachusetts investor Seth Klarman. Only one other person contributed more than $25 to the super PAC.

Gay Republican candidates are running in three of the national party's top-targeted races this year. Should any of them win, they would be the first openly gay Republicans to win election to Congress.