"Hard line" (a term I think I've only really seen applied to Politburo cronies, Chinese officials, or grisly dictators -- oh, and Tom DeLay).
"Divisive"
"Watchdog"
"Doctrinaire"
Just some of the few appellations being attributed to our fine Pontiff. Jonathan Last gives a great run-down of the media's take on this man. How many derogatory terms can you apply in one sentence and get away with it?