The largest LGBT advocacy group in Iowa has already collected more than 1,000 signatures demanding an apology from Bob Vander Plaats, head of the conservative Christian organization The Family Leader, only 24 hours after launching the petition.

ThinkProgress released video Tuesday of Vander Plaats erupting in laughter and saying, "That's pretty good," after someone makes the joke: "You know what my wife says? She says: Iowa, the state where you can't smoke a fag, but you can marry one."

His organization created the controversial marriage pledge, which was signed by Republican presidential candidates Michele Bachmann and Rick Santorum.

The petition calls on Vander Plaats to apologize for his "hurtful and derogatory language."

"The bullying tactics of Bob Vander Plaats and the Family Leader have gone too far," said Troy Price, One Iowa Executive Director. "The overwhelming response we have seen shows just how Vander Plaats' actions have hurt loving, committed couples and their families across the state. This type of language has no place in the conversation about marriage. Bob Vander Plaats must apologize to the thousands of Iowans he has offended with his actions."

Vander Plaats has not yet commented on the video.

"Rarely does Vander Plaats shy away from the spotlight," said Price. "If Vander Plaats truly feels that this sort of language is appropriate, then he should come out and say so. But, if he feels--like so many Iowans do--that derogatory and shameful language like this does not belong in this discussion, he should apologize, and apologize quickly."

Those who signed the Family Leader marriage pledge vowed to remain faithful to their spouses and support a constitutional amendment banning same sex marriage, as well as agreeing that same sex marriage was akin to polygamy.

They both also promised to ban "all forms of pornography and prostitution, infanticide, abortion and other types of coercion or stolen innocence" and only appoint conservative judges.

Adding to the controversy surrounding the pledge, the original version of the document signed by Bachmann and Santorum claimed that African American children were in some respects better off under slavery than they are today, but that portion was later removed.

Republican presidential candidates Ron Paul, Gary Johnson, Mitt Romney, Tim Pawlenty, Newt Gingrich, Jon Huntsman, and Herman Cain refused to sign the pledge.

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