A previously suppressed ad featuring Chelsea Clinton endorsing gay marriage has surfaced.

The 45-second ad was filmed as part of a TheFour2012.com campaign to promote marriage equality in four states. Last November, Maine, Maryland and Washington state approved referendums legalizing such unions, while Minnesota voters became the first in the nation to reject a constitutional amendment defining marriage as a heterosexual union.

Voters in those states never did see the ad.

“I believe that everyone should have the freedom to marry the person they love,” Clinton says in the ad. “I hope you'll join me and others who care about basic fairness and civil rights by doing all you can to support these efforts no matter where you live. The outcome in these four states is so important.”

(Watch the video at BuzzFeed.com.)

BuzzFeed.com, which first reported on the ad, quoted an anonymous source as saying that NBC, Clinton's employer, “scuttled” the campaign.

A previous The New York Post story cited Clinton's NBC News contract as preventing her from campaigning for President Barack Obama's reelection campaign.

Clinton, along with her famous father, President Bill Clinton, visibly campaigned for passage of marriage equality in New York. She joined NBC News as a “special correspondent” in 2011. Clinton's reporting at the network avoids politics.