THR.com is reporting that for the Wednesday appearance of Senator Obama:
"Late Show" averaged a 4.1 rating/10 share in the Nielsen Media Research metered markets, the second-highest rating the show has received all year. Wednesday night's show managed to do the often out of reach, which was to beat late-night king Jay Leno and "The Tonight Show." But it wasn't by much, as Leno averaged a 3.9/10.
read the rest here.