For a few years, I've felt a certain strange affection for Susan Sontag that has a lot to do with a simple travel accident: we were both in Berlin on September 11, 2001 (consider your question answered, Alan Jackson), and based on an interview she later gave to Salon, I know she had the same experience I did: bleary, jetlagged hours watching CNN and BBC Worldnews. There was nothing else TO do; everything anyone might have done for distraction had been closed. And so once the panicked phone calls to loved ones had gotten through, and with no flights home to jump on because nothing was moving, all that was left were equally dazed companions and CNN. So as small a thing as it is, and as many NY area folk are in Berlin at any one time, I felt that strange click of a common experience (I do like to think that Susan Sontag didn't find out about the attacks on the goddamn UBahn, though). But the reason that translated into admiration is that her response was so much more clear-sighted, more intelligent, and more demanding of our leaders, our media, and us as a people than mine was.
Yes, I'm talking about the brief New Yorker piece for which she was excoriated and branded a fifth columnist--this is what made me love this woman, rather than the work of hers I'd read in the course of my studies. Her demand was a simple one: treat Americans like adults.
I can't recall any other figure of her cultural weight referring to America as a "mature democracy", and I certainly can't remember any cable news pundit using the phrase. Maybe they're afraid; if they repeated it too often, Americans might actually come to believe it and to demand a fourth estate worthy of it.