Secular right commentators are always banging-on about the Christian nature and roots of PC.
This is correct, but - being secular - they completely misunderstand, indeed invert, the meaning of being Post-Christian.
The secular right emphasizes the Christian elements in PC - residual from Christianity.
But this is entirely to misunderstand.
The proper emphasis is on the Post, not on the Christian.
It is the fact that PC has rejected Christianity which is of significance; not that PC retains some scattered aspects of Christian ethics.
Specifically, it is the rejection of the pre-requisites of Christianity which cause the problem of PC.
In particular, there is underlying PC a nihilistic rejection of reality; this was caused when Christianity was rejected.
(In order to get rid of Christianity) what was rejected was a whole way of orientating humanity in reality: most of it pagan, some of it monotheistic, a relatively small amount of it being specifically Christian.
So, PC Post-Christianity is not just Post-Christian, but also Post-Monotheist and Post-Pagan. None of these traditional religious perspectives make any kind of sense to PC.
So PC Post-Christians reject the soul, life after death, reality, the possibility of knowledge of reality, the possibility of God, the possibility of revelation, miracles, prophecy...and so on and on.
It is being 'Post' all-this-stuff that is the problem about PC - and it really has nothing to do with the Christian elements residual in PC.