Rick Santorum has said that legalizing gay marriage would lead to America's failure.

The 53-year-old Santorum made his remarks Saturday at the Thanksgiving Family Forum in Des Moines, Iowa. Also attending the event were Newt Gingrich, Herman Cain, Rick Perry, Ron Paul and Michele Bachmann. Former Massachusetts Governor Mitt Romney was invited but did not attend. Also not in attendance was former Utah Governor Jon Huntsman, who has not placed an emphasis on Iowa.

Moderator Frank Luntz conversed with the candidates as they gathered around a dinner table festooned with pumpkins. About 3,000 people attended the forum.

The former Pennsylvania Senator insisted that the states should not be allowed to decide on marriage.

“We have to fight the battles in the states,” Santorum said. “We cannot defer. We can't say, 'The 10th Amendment, they can do what they want.' This is too important for that. There's a basic and central value. The family is the bedrock of our society. Unless we protect it with the institution of marriage, our country will fall.” (The video is embedded in the right panel of this page.)

(Related: Ron Paul out of step on gay marriage amendment at Christian forum.)