Stephen Colbert is still No. 1 in late-night total viewers -- and he’s closing in on Jimmy Fallon in the key 18-49 demo

The New York Times

A year ago, Fallon’s Tonight Show topped Colbert’s Late Show by 364,000 viewers in the all-important 18-49 demographic. In the just-completed November sweeps, Fallon's lead has collapsed to 57,000, the closest that Colbert has been to Fallon in that demo. In fact, as The New York Times notes, Fallon has plunged 26% in that demographic even though he is the youngest of the 11:35 hosts at age 43.