Republican presidential candidate Rick Santorum says he wants a uniform marriage definition throughout the United States.

Appearing Monday at a breakfast in Washington hosted by the Christian Science Monitor, Santorum, an outspoken opponent of marriage equality, said that allowing states to define marriage would create “too much confusion.”

“I believe we need a national standard for marriage,” Santorum told reporters. “I don't think we can have a standard from one state to another on what marriage is.” He added that he wants “to define marriage the way it was defined for 4,000 years of human history.”

Texas Senator Ted Cruz and Wisconsin Governor Scott Walker have each backed a constitutional amendment which would allow individual states to decide the issue. Cruz has already introduced such a measure.

“I think that's a mistake,” Santorum said of the proposed amendment. “I argued that 10 years ago when others wanted to do that 10 years ago. You can't have a hodgepodge of marriage … it just creates too much confusion out there on a variety of different levels.”