He's a former seminarian, if not a priest as I recall.
The Arabist claim you see on the thread is "hollow". The second Yasser Arafat or one of his gumbahs does something to upset the Pope, you will see McLaughlin move in a different direction.
Part of this arises out of the issue of Catholics praying for the souls of dead Jews at the site of a German deathcamp in Poland. John didn't like Jews suggesting that Catholic prayers weren't heard by God. Neither did Buchanan. I think even Eleanor spoke up on that issue.
None of it conforms to my belief system so it didn't worry me a bit ~ on the other hand, it drove McLaughlin even further into the Catholic "camp" (a sarcastic comment if I ever made one!).