On Meet the Press with David Gregory this weekend Hermain Cain said:

MR. GREGORY: [...] Same sex marriage. Would you seek a constitutional ban for same sex marriage?

MR. CAIN: I wouldn't seek a constitutional ban for same sex marriage, but I am pro traditional marriage.

MR. GREGORY: But you would let the states make up their own mind as they're doing now?

MR. CAIN: They would make up their own minds, yes.

Rick Santorum responded in a press release:

"I have been a long-time advocate for states' rights. However, I believe as Abraham Lincoln did - that states don't have the rights to legalize moral wrongs. Mr. Cain, Congresswoman Bachmann and Governor Perry all believe 50 different definitions of marriage is fine, I strongly disagree and will continue fighting for traditional marriage between one man and woman."

... Senator Santorum is one of the original sponsors of the Federal Marriage Amendment and the nation's leading advocate for the traditional American family. As a presidential candidate, Senator Santorum proudly signed the National Organization for Marriage's "Pro-Marriage Pledge," which Mr. Cain refused to sign. Last fall, Senator Santorum was the only 2012 presidential contender to travel to Iowa and campaign in opposition to Iowa State Supreme Court Justices who decided to take it upon themselves to redefine marriage.