If he isn't senile now, that suggests he's always had pablum for brains but older interviews don't really hold that out.
Even if he doesn't meet the diagnostic criteria for a specific form of dementia, the man seems to clearly suffering from obvious mental decline. Further, he shows evidence of sundowning with his regular agitated and confused evening/late-night social media dumps.
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The Party told you to reject the evidence of your eyes and ears. It was their final, most essential command.
If you're not careful, the newspapers will have you hating the people who are being oppressed, and loving the people who are doing the oppressing. —Malcolm X
Real power is achieved when the ruling class controls the material essentials of life, granting and withholding them from the masses as if they were privileges.—George Orwell