He was named Grand Marshall before the gay group was allowed in. The parade is not until March, perhaps he will reconsider. In the mean time. Half this country agrees with him. What do you propose we do about that? It’s really easy to throw the words and the Bible verses around but that really does not solve the problem does it?
Doesn't matter if the whole country agrees with him (unless one's religious beliefs are informed by popular opinion rather than immutable Truth).
His participation will telegraph tacit approval and as such will constitute a betrayal of the Faith he claims to represent.