A marriage is a union between a man and a woman. You would have to redefine marriage.
It would be like changing the definition of “African American” to include white people so whites could get contracts geared towards the African American community.
“African-american” is a totally stupid phrase. I know and once worked with a white male from Uganda, now a citizen of the U.S. and a full-fledged “African-american.” Labels like that are, besides stupid, self-defeating.