This second-by-second data shows viewership by cable network and network affiliates. You can see that at 9 p.m. ET, NBC and Fox News have about the same audience, before Fox News starts to jump during the speech, and holding steady the rest of the night.
CNN, MSNBC and PBS did the best job of holding on to their audience. This is not surprising considering their viewers are news and information junkies.
The biggest drop off came from those watching FOX broadcasting, with viewership plunging after the president finished speaking at 10:30 p.m. ET. It’s fair to say some of those viewers changed the channel to see post-speech analysis, while others moved on from politics altogether.
This data comes from nearly 8 million smart TVs made by Vizio, assembled by Inscape. While still a fraction of overall viewership, this is the largest opt-in population of smart TV data in the U.S.