"I'm sure you could go back and read stories, oh, you know, 'The Republican party's going to change. This is the future,'" Santorum told the Des Moines Register. "Obviously that didn't happen. I think you're going to see the same stories written now and it's not going to happen."
"The Republican party's not going to change on this issue. In my opinion it would be suicidal if it did."
Santorum scoffed at the recent reversals from Sens. Rob Portman, R-Ohio, and Mark Kirk, R-Ill. on gay marriage, dismissing their actions as "splintering" and fringe.
"Just because some of those things happen to be popular right now doesn't mean the Republican Party should follow suit," he said.
Calling landmark abortion case Roe v. Wade a "mistake," Santorum said he was hopeful the Supreme Court had "learned its lesson about trying to predict where the American public is going" to rule against same-sex marriage in the cases it is currently considering.
Although Santorum is in the all-important Iowa next week, a state he won by the slimmest of margins in the 2012 Republican primary, he said he had not made up his mind about running for president again in 2016.