I happen to agree with the views they have stated in the past. Marriage (defined as being between one man and one woman) is one of the most foundational institutions in the world and is worth defending.
My marriage is just as valid as anyone else’s. And it’s incredily offensive to suggest that my marriage is somehow an attack on marriage itself. Your view is bigotry in an old, familiar form, and can only be defended based on religion, which has no role in limiting civil rights within our secular society.