This issue is either left up to the states or it is federalized.
Given Priebus’ comments, and when you look at both statements “you can’t federalize that kind of mandate” and “the individual states can make that decision on their own, Romney has tossed his pledge for a constitutional amendment banning same-sex marriage under the bus, along with almost every other promise he has made to the base of the GOP.
What role would Romney play in any federal constitutional amendment process? Last I saw, the president can criticize or praise it, but doesn’t get any legal say.