There are cynical propagandists, but there are also people who more or less believe what they say, and may therefore be even more dangerous.

A Mudcat poster (I forgot who) held the opinion that even Hitler believed himself to be a "good guy". I am not quite convinced, but most people with a "moral compass" are quite good at justifying their actions for themselves. Even if we find their moral excuses valid, we must not praise their errors.