@BrianJopek
And it just occurred to me...when Trump dies this coming summer, JD Vance will be set to remain in office until 2035, because he was not elected POTUS and can run for office twice.
@Threadbane Actually, it would have to be 21 January 2027 or later. If a VP takes over less than halfway through an incumbent's term, then that counts as one whole term. (The law does not count partial terms, only whole, by rounding.) You're right about the ten years, if he takes over at least halfway through. But it must be at least that far. Otherwise, the best he can get is less than eight.
The same is true no matter WHY he steps in, only IF he does. So 25A wouldn't change this math.