What did wedding florists offer in 2015 BC?

Serial presidential candidate Rick Santorum calls for a national standard for marriage, failing to notice we already have one:

Republican presidential candidate Rick Santorum said Monday he wants a constitutional amendment that defines marriage as between a man and a woman in all 50 states, less than three weeks after the Supreme Court legalized same-sex 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 in Washington hosted by the Christian Science Monitor, adding that he wants “to define marriage the way it was defined for 4,000 years of human history.”

Why can't conservatives decide when marriage began? Santorum's iteration is now 4,000 years.