They didn't. Hitler fired Julius Streicher very early from any government position because he was so extreme that even Adolph himself could stomach him. Streicher tried to use this fact in his defense at Nuremberg, but he was ordered to dance the Tyburn Jig anyway because his writing was so central to the formation of Nazi attitudes which led to their crimes against humanity.
Pravda was also famous for actually criticizing the Politburo once in awhile.
When Pravda criticized the Politburo, was it on behalf of the Supreme Soviet?