Catholics of a certain age may have an image of the young priest, maybe a Jesuit, who introduced himself not as Father O’Reilly but as “Kevin.” Father Kevin — “please, just Kevin” — is the one who introduced the guitar mass when he got his own parish.

That young priest is now old, and the traits of the boomer priest — politically active, politically liberal, unconstrained by strict ideas about liturgy and tradition — are steadily disappearing from the priesthood.