The key to your nonsense idea that wanting to striping an entire class of people of a right (and materially supporting the effort) is simply a "dissenting opinion that offends them". It isn't offensive, that trivializes it. It is a legal attack on class of people.
If he had donated $1000 to a group to reintroduce segregation in public schools, I highly doubt you would defend him under the idea "he just has a dissenting opinion that races shouldn't mix and materially supported the effort" -- or would you?