Hot take: It's a lot easier to persuade people when you're willing to make stuff up to support your argument.
Lukewarm take: One of the important hidden factors here is the impact of channel location. They find that the lower channel number FNC has, the more viewers it has and the higher chance of persuading those viewers is. And because there currently doesn't appear to be political calculations or demographics involved in deciding the channel position, that gives a lot of power to the cable companies on what seems to be just a "random" decision. I wouldn't be surprised if parties and the channels themselves start lobbying for lower channel positions if they get word of this, which would be even more insidious to our body politic than Citizens United.
Ice-cold take: There's nothing like trying to read a study written by an economist to sap all of the energy out of you until all that's left of your body is a frigid, lifeless husk and your soul a barren wasteland temporarily beyond all hope of redemption.