Republican presidential candidate Rick Santorum on Wednesday pledged that as president he would fight a Supreme Court ruling striking down state bans on gay marriage.

The high court will hand down a ruling this month in a case challenging bans in Ohio, Michigan, Kentucky and Tennessee. The decision could strike down the nation's remaining 13 bans, leading to nationwide marriage equality.

Santorum, who is currently campaigning in Iowa, called in to Glenn Beck's radio program.

(Related: Rick Santorum warns tiny turnout in Iowa about gay marriage.)

Beck warned listeners that marriage equality would lead to churches being forced by the government to marry gay and lesbian couples.

When asked how he would respond as president, Santorum answered that such a ruling would be unconstitutional.

“This is tantamount to government establishing religion,” Santorum said. “When the United States government comes in and says this is what you are going to believe, this is how you're going to practice your faith, this is a new religion. This violates, in my opinion, the Establishment Clause in the Constitution that says that Congress shall make no law with respect to an establishment of religion. If the government goes around and tells churches what they have to believe in and what their doctrine is, that is something that is a violation of the First Amendment.”

“If they get it wrong and the consequences are what I suspect they will be toward people of faith,” Santorum added, “then this president will fight back.”