A key data point from Frank Rich's profile of Fox News:
Fox News is losing younger viewers at an even faster rate than its competitors. With a median viewer age now at 68 according to Nielsen data through mid-January (compared with 60 for MSNBC and CNN, and 62 to 64 for the broadcast networks), Fox is in essence a retirement community ... If it is actuarially possible, its median viewer age will keep creeping upward. (It rose by two years over the course of 2013.)
It's satisfying for liberals to call Fox News "a retirement community," and, surely, it is. But the entire cable news industry relies on building a product for ages 60 and up. MSNBC isn't exactly a nursery.
Various media critics (both professionals of the trade and those who critique for free) like to mock CNN for its poop-ships and long decline, and we chastise MSNBC for trying to play Fox's game from the left with longer words and fewer viewers. But, fundamentally, Fox News is at an unassailable advantage on its turf because it's selling a conservative political product to an older audience, which tends to be more politically conservative, anyway. Over the last three general-election cycles, the 65+ group voted for the GOP presidential candidate by an average of 9 percentage points.
Roger Ailes is some kind of genius, and Fox News gets many things right when it comes to building telegenic politico-entertainment. But maybe Fox's secret sauce isn't TV. It's demographics.