I do not agree with his basic premise: The campaigners against the pope’s visit have more in common with the fanatical Inquisitors of old than with Enlightened liberal humanists.
I would submit that intolerance is a necessary end to enlightenment liberal humanism.
The very rejection of absolutes is a form of "orthodoxy," in of itself: its rejection of dogma is dogmatic in nature and its requirement for "tolerance" is necessarily penalized with medicinal and expiatory penalties for public heretics to that dogma -- without the structure of a canon law to prevent their own variety of witch-burnings.
And, as it stands, they are too blind to see what they have constructed.
Unlike, say, the Inquisition, liberal-humanist intolerance is unrestrained by anything like canon law --- historically, the major source of procedural due process in the West. In this country, their witch-hunting is limited by custom and Constitution only to the extent that they haven't been able to knock them flat (yet) --- though they've been undermining them from within and pounding on them from without for decades.
What the Pope is doing in Britain is very interesting. To switch metaphors, I think more and more that he's our Frodo within the Black Gates of Mordor.