Texas Governor Rick Perry has become the latest Republican presidential candidate to sign a pledge from the National Organization for Marriage (NOM), according to On Top Magazine. The group is dedicated to fighting same sex marriage and preventing same sex couples from adopting children.

"Kudos to Gov. Rick Perry for making it clear: he's a marriage champion," said Brian Brown, president of NOM. "The purpose of NOM's Marriage Pledge is to move from vague values statements to concrete actions to protect marriage."

Republican candidates Michele Bachmann, Rick Santorum and Mitt Romney have also signed the pledge, vowing to support a federal marriage amendment defining marriage as one man and one woman.

By signing NOM's marriage pledge, the candidates also vowed to protect the Defense of Marriage Act in court, appoint conservative judges and a conservative attorney general, create a presidential commission to investigate harassment of same sex marriage opponents and put same sex marriage up to a vote in D.C.

"Perry makes crystal clear that, contrary to the conventional wisdom, gay marriage is going to be a bigger issue in 2012 than it was in 2008, because the difference between the GOP nominee and Pres. Obama is going to be large and clear," Brown added. "We look forward to demonstrating that being for marriage is a winning position for a presidential candidate."

The NOM pledge is similar to another pledge from The Family Leader, a Iowa-based Christian conservative group. Bachmann and Santorum were the only two presidential candidates to sign the Family Leader pledge, which drew large amounts of criticism.