President Barack Obama tells Robin Roberts of ABC's "Good Morning America" on May 9 that he supports same-sex marriage.  Editor's note: Brian Brown is the president of the National Organization for Marriage, a nonprofit organization that opposes same-sex marriage and serves as a resource for marriage-related initiatives at the state and local level.  (CNN) -- North Carolina is so important to the re-election chances of Barack Obama that he picked Charlotte as the host city for the Democratic nominating convention.  On May 8, all his careful plans came crashing down when 61% of voters in a North Carolina referendum adopted a constitutional amendment defining marriage as the union of one man and one woman.  Pre-election polls showed that a majority of Democratic voters supported this amendment, as did independents and an overwhelming majority of African-Americans and Republicans.  Before the N.C. vote, Obama publicly opposed Amendment One, and gay activists used this in an attempt to rally Democrats and independents, and especially African-Americans, to oppose the measure.  This failed miserably, and when polls started to predict Amendment One would pass, Obama canceled an Election Day trip to the state. Then Vice President Joe Biden popped off that he saw no problem with same-sex marriage. Finally, a day after the North Carolina vote, Obama admitted what had been obvious for a long time -- he supports redefining marriage.  Obama's embrace of same-sex marriage will help ensure he becomes a one-term president, and his political demise will begin with North Carolina.  Follow @CNNOpinion on Twitter and Facebook.com/cnnopinion  Despite what many in the media claim, the American people do not support same-sex marriage. They sure as heck don't in North Carolina, where voters made it clear they want to prevent activist judges and politicians like Obama from redefining marriage.  The National Organization for Marriage, which I head, helped lead the North Carolina campaign. Our victory for marriage was so impressive that the prominent Democratic Public Policy Polling firm sent out this Twitter missive as the results came in: "Hate to say it, but I don't believe polls showing majority support for gay marriage nationally. Any time there's a vote, it doesn't back it up."  Support for traditional marriage in North Carolina and across the nation is heavily rooted in the faith traditions of voters. In 2008, candidate Obama acknowledged that as a Christian, "God's in the mix" when it comes to understanding the definition of marriage.  Where is God now in his political calculation? It seems he's decided to ignore what the creator says about marriage and base his flip-flop on generalities about the "Golden Rule."  Regardless, endorsing gay marriage isn't going to fly in North Carolina, and it isn't going to fly in any of the other swing states that have marriage amendments on the books -- including Ohio, Virginia, Florida, Colorado and Nevada -- all adopted by voters.  Obama is now claiming that he supports the "concept" of states deciding the marriage issue themselves. His administration has agreed to enforce the 1996 Defense of Marriage Act, which is the legal framework that allows a state to control its own definition of marriage and avoid having to recognize same-sex marriages performed elsewhere. But the White House has refused to defend the law in federal court.  If Obama gets his way and DOMA is overturned, it's only a matter of time before marriage is redefined for the entire country. Now he has signed up as an official cheerleader for that outcome.  As if that wasn't enough, same-sex marriage radicals will descend on Charlotte and demand that the cause become a central plank of the Democratic Party platform. Nancy Pelosi is already enthusiastic about the prospect.  The president has tied his presidency to a cause that has never been successful with voters -- not in a single state -- not at any time. Not in blue states such as California and certainly not in swing states such as North Carolina.  What Obama has just succeeded in doing is to give an incredibly powerful reason to hundreds of thousands of social conservatives, and especially evangelicals, across America to rally behind Mitt Romney if they want to preserve marriage -- and they most decidedly do want to preserve marriage.  The people of faith in America know that the future of marriage is on the line, and as has been proved in 32 votes across this nation, they will not fail the cause of marriage.  The opinions expressed in this commentary are solely those of Brian Brown.
Brian Brown: President Obama has taken up a cause rejected by the majority of Americans, who have never supported same-sex marriage in a state referendum.