I don't think that you should feel ashamed unless you have supported the ones in that wing of the party, which I doubt that you did.
In case you missed it earlier, I tell people that I am reluctantly a Republican. I support the platform of the party. I just don't support the many politicians who claim to be Republican, but don't support or agree with the platform.
Only when a good candidate is available will I support them with my efforts and my money. I refuse to support an "R" that doesn't have the same world view that I hold and will not carry the shame that they generate with their actions. If an "R" and a "D" are going to do the same thing, I would rather have the "D" get the blame for it than the "R". That way people will know the difference between the two.