The Supreme Court is expected to issue a decision this month that could grant, for once and for all, same-sex couples the right to wed across the country. But Walker said on ABC’s “This Week” that he would support amending the constitution to protect states that still want to ban same-sex marriage.

“I personally believe that marriage is between one man and one woman,” Walker, a prospective GOP presidential candidate, said. “If the court decides that, the only next approach is for those who are supporters of marriage being defined as between one man and one woman is ultimately to consider pursuing a constitutional amendment.”

He added that “the decision on defining marriage should be left up to the states.”