Brian Brown, president of the National Organization for Marriage (NOM), on Friday urged members to reject President Barack Obama for a second term because he would work to legalize gay marriage.

In a lengthy blog post published at NOM's website, Brown predicted a “historic national victory for marriage” on November 6.

“Just 10 days until the polls close, when Americans will choose,” Brown wrote. “The future of our country – and also the future of marriage – could be decided for generations to come.”

“Nationally, Americans will choose between Mitt Romney, a pro-marriage candidate for President who will defend DOMA [the Defense of Marriage Act] and appoint judges that respect our Constitutional values; or the openly pro-gay marriage incumbent, Barack Obama, who has surreptitiously undermined the legal defense of marriage for four years and who, if he gets a second term, will have the power to position a fifth vote on the Supreme Court to invent a right to gay marriage and insert it in our founding document.”

Brown acknowledged the narrow leads marriage equality supporters hold in Maine, Minnesota, Maryland and Washington state, saying that “If you and I were a conventional political movement, we would be feeling pretty overwhelmed right now, depressed and in a defensive crouch.”

“A few stones, a slingshot and faith – that's all it took for David to topple Goliath,” he added.