Adrenochrome.

Because he’s probably the pharmaceutical equivalent of Bernie from weekend at Bernie’s.

I’m sure he’s on a tailored cocktail of drugs, provided by the government healthcare he gets, that’s designed to give him the best quality of life possible. All well and good for a man who should be enjoying the last years of retirement. I’m sure most of that cocktail comes with the stipulation that he shouldn’t operate heavy machinery though, so if they release his medical records it’ll be obvious to anyone with two neurons that if he’s no longer qualified to operate a golf cart, maybe he shouldn’t be driving the entire country.

Clearly he gets a weekly booster shot to cheat death.