The National Organization for Marriage (NOM), the nation's most vociferous opponent of gay marriage, has launched a campaign attacking President Barack Obama for his decision to no longer defend the Defense of Marriage Act (DOMA) in court.

DOMA bans federal recognition of the legal marriages of gay and lesbian couples, barring gay couples from access to thousands of federal benefits.

In a one-minute-twenty-three-second video released Monday, NOM accuses the president of turning his back on marriage.

“DOMA was passed by an overwhelming bipartisan majority and signed into law by President Clinton, but that didn't seem to matter to Obama,” the male announcer says in the ad. “Instead of doing his job to uphold the law he's dumping it behind our backs.” (The video is embedded in the right panel of this page.)

Not mentioned in the ad are the facts that Clinton has since said he was “wrong” to sign the law, the bill's author, former Georgia Representative Bob Barr, a Republican turned Libertarian, has called for the law's repeal, and a number of Democratic lawmakers who voted for DOMA have since had a change of heart. The most recent being Washington Senator Patty Murray.

At NOM's website DefendDOMA.com, the group urges supporters to oppose New York Representative Jerrold Nadler's bill that would repeal DOMA and support Missouri Representative Vicky Hartzler's resolution that would force the administration to defend the law.