Boarding a train into Manhattan on Monday night, I found myself in a seat (rare in itself) across from an Oxford-wearing twenty-something engrossed in Harry Potter and the Order of the Phoenix, the fifth tale in the series, released just last week in theaters. Aside from checking the stops occasionally, he never looked up from his book.

Shortly later I transferred trains; a woman, maybe 50, sat down across from me. She too pulled out a book -- Harry Potter and the Prisoner of Azkaban, Potter's third book.

Potter's ubiquity reminds this Muggle of critic Chuck Klosterman's notes on the death of Johnny Carson and the popular notion that there could never be another Carson, who in his day had such a wide and total grasp on the nation. Klosterman argued that of course there could be another Carson, except that through the fragmenting and stratification of popular culture -- augured by the niche channels of cable television, taken to extremes by the internet -- we have instead chosen to retreat into cultural cliques, limiting common experience to -- what? Devastating acts of terror, I guess.

As I recall, Outkast's massive 2003 hit song "Hey Ya!" was the closest thing Klosterman could propose as a unifying cultural force (not without his reservations), but he might have overlooked J.K. Rowling's little wizard. Who since maybe The Beatles has met this sort of worldwide fanfare with each new offering? Publisher Scholastic (NASDAQ: SCHL) is delivering a record-breaking first-print run of 12 million U.S. copies to meet demand -- that's a copy of Harry Potter and the Deathly Hallows for every ninth household.