Well, if you can get the general public at each other's throats through driving them into ever wider polarities, it helps keep them off your back. If you can make them think of each other only as the most extreme and ridiculous caricatures of "Right" and "Left", so much the better. They'll be too afraid of each other to even bother talking about anything in a reasonable way to one another...and they'll totally miss the fact that they all want justice, fairness, and truth from their government, and they have much more in common than they realize.

It's like a community of mice tearing each other up while the overstuffed cat sits comfy in his mansion and contemplates his dinner with a Cheshire grin.