This constant lying is not aimed at making the people believe a lie, but at ensuring that no one believes anything anymore.

 A people that can no longer distinguish between truth and lies cannot distinguish between right and wrong. And such a people, deprived of the power to think and judge, is, without knowing and willing it, completely subjected to the rule of lies.

 With such a people, you can do whatever you want.

—Hannah Arendt

(this keeps coming up, and the reason is indubitably obvious to even the most casual of observers.)