Well, have a post war President pull a Grover Cleveland a serve two non consecutive terms. It can be a one term President (Ford, Carter, Bush 41) or a two term President (Ike, Nixon, Reagan, Clinton, Bush 43, Obama) losing their re election bids OTL and giving it a try four years after their defeat.
My guess is the easiest way to it is have Ford run in 1980 by having Reagan win the primary in '76 and lose the general to Carter, or have Reagan sit the '80 election out for health reasons, or scandal.
My guess is the easiest way to it is have Ford run in 1980 by having Reagan win the primary in '76 and lose the general to Carter, or have Reagan sit the '80 election out for health reasons, or scandal.