Ah, now I have to agree with you! He is destroying the Republican Party, but only as you and I know it! The Republican Party has destroyed itself much earlier (maybe a few decades now).
Our problem is trying to either resurrect the Republican Party or starting a new party. Seems to me that the only choice is a NEW Party (see Tea Party).
Yes, scary as it seems, we are no longer in control or have any influence within the Republican Party. It is past time to forget them and move on...
What the Republican Party today is akin to the Democrats - stay in power and control the money. It has little to do with morality, philosophy, commitment. It seems to be all about political power and it infects both parties.