The whole "Fox has the best ratings on cable" (note..."cable") thing from the Right...is easily explained in an analogy.
Imagine a small town where there are five ice cream shops. ONLY ONE sells pistachio. Just one.
The ice cream buyers in the town who DO like pistachio go to that ONE ice cream parlor.
The ice cream buyers in the town who DON'T like pistachio but perfer other flavors SPLIT between the other four shops.
Thus to the eye, the ONE pistacho-carrying ice cream parlor is "the most popular ice cream parlor."