Party planks don’t mean much.
The union could come with things like implied power of attorney and certain tax benefits similar to marriage in some respects, but different in others. This way, marriage stays marriage (life long union between one man and one woman) and is designed to be the foundation of a family, and other folks not interested in that arrangement can still face life's challenges as part of a team rather than alone (and are thus less likely to end up on public assistance). Everyone wins.
So long as civil unions are considered same sex “marriage” for gay people, this pointless battle over the word “marriage” will never end.
Good for the GOP.
Actually good for the few real conservatives like Tony Perkins for standing up and insisting that the Party at least continue appear actually, you know, conservative.