Here's a theoretical conundrum we're having here.
Say that a day after he is elected, the US President is assassinated.
The VP is sworn in as President, yes. And he can campaign for re-election to the Presidency at the next election.
But can he campaign for a further re-election in another four years? Is he allowed the regular two Presidential terms, or is he restricted on account of his initial Vice Presidency?
Get on it Ho_Fo.