Anyone with half a brain cell knows that he is a pathological liar. And even worse than being a pathological liar, he's a pathological "truth bender". At no point is he lying, and at no point is he ever telling the truth. This gives him a method to worm his way out of any verbal snafu he found himself in. He learned it by emulating his sociopathic father, and he taught his children the same trick.
Are you sure trump isn't also a sociopath? He doesn't care if his actions kill people, or hurt others, really unless it hurts him personally, he doesn't give a shit about anything else.
The true mind can weather all the lies and illusions without being lost. The true heart can tough the poison of hatred without being harmed. Since beginningless time, darkness thrives in the void, but always yields to purifying light.
In the era before the Avatar, we bent not the elements, but the truth within ourselves. To bend another's truth, your own spirit must be unbendable, or you will be corrupted and destroyed.