David Letterman has gotten his second wind:

The bad boy of Ball State, Huck Finn grown and weathered, David Letterman has become the national Daddy. He is the ideal dad for the age—not a particularly pristine dad, or full of Cronkitean certitude, but confused and serious and full of conflict, anger, and ambiguity. Letterman is not a fuzzy person; working live he gives off the kind of dangerous electricity of stripped, dangling power lines. But he is a fundamentally serious comedian holding onto the gig of his life—Late Show With David Letterman—the hour in his day that seems to give him purpose.

I’ve never read a better account of just what it is that makes Letterman so great.

His show was a constant in my life growing up. Huddled in my room, head down in homework, up too late, I’d watch the flickering visual trick box as Letterman seemed at once to be in his own world and in mine. Laughing internally and externally. Amusing himself while trying to amuse me.

His recent growth as a national backbone, during last year’s presidential campaign and thereafter as he swatted down the Palin cult of outrage, has shown he’s on his way to being an icon in a way Jay Leno never will be:

“Cat jokes work,” The Wall Street Journal reported on him, as he tested new material in Boston this summer. “Edible underwear doesn’t.” His incessant shtick and weightless political attacks have made him a risk-free franchise. Of course President Obama visited his couch in Burbank. “I don’t like the edgy comics out there,” Deb Stoddard of Natick, Massachusetts, told the Journal. But she loves Jay Leno.