Former Sen. Rick Santorum (R-PA) put some daylight between himself and other 2016 contenders who are calling for a constitutional amendment to scale back the Supreme Court’s same-sex marriage decision. Unlike Sen. Ted Cruz (R-TX) and Gov. Scott Walker (R-WI) — who are calling for a constitutional amendment that would allow states to decide whether they would like to ban gay marriage — Santorum is calling for an amendment that would prohibit gay marriage nationwide.

“I believe we need a national standard for marriage. I don’t think we can have a standard from one state to another on what marriage is,” Santorum told reporters at a breakfast event Monday in Washington hosted by the Christian Science Monitor.

When he was in the Senate, Santorum campaigned for a 2004 proposed amendment that would have limited marriage to opposite-sex couples. That bill failed to get the two-thirds support required to advance out of Congress.

Santorum called a measure that would allow states to decide a “mistake.”

“I argued that 10 years ago when others wanted to do that 10 years go. You can’t have a hodgepodge of marriage,” Santorum said. “One of the reasons the court decided the way they decided is because they recognized you couldn’t have different marriage laws in different states. It just causes — it just creates too much confusion out there.”