What, exactly, do you think ought to happen if 50%+1 of the electorate votes for a blatantly un-Constitutional infringement of the rights of the other 50%-1? Should the Constitution be ignored? Should there be armed revolt? What?
No. I do not think the Constitution should be ignored. But I don't think it is some sort of "living document" that changes at the whim of a judge. The fact that no one on earth can say what the "priveleges and immunities" are, means that we have a choice.
We can let the judges apply any meaning they want to the phrase and overturn any law they don't like. Or we can say it cannot be used to overturn any law.
Personally, I'd rather the people make the laws -- not the judges.
Well, then, you shouldn't defend the evasion of the Privileges and Immunities Clause by judicial whim.