I can’t find fault with the line of thought, but I think you are missing a piece of the propaganda machine. Network programming is an integral part of it.
The average FReeper, I suspect, does not spend much time watching junk like “Glee”, “Modern Family”, and “The Today Show”, but there are millions of citizens who do. Through such programs, the left relentlessly promotes its ideology.
You are correct about the viewing. They may be older and dwindling, but they voted in November.
While I can't speak for Greenfield, I think that's something we are all aware of, including him. I read the article to say this is not a one-stop solution. After all, this is a war, again, as we all know, and it's going to take multiple tactics on multiple fronts - in multiple battles, to be successful.