Amid rampant speculation that Trump will run again in 2024 I found this fairly interesting:
The majority of US Presidents have severed less than 2 full terms. Only one (Grover Cleveland) has lost as the incumbent and gone on to win a second (non-consecutive) term.
I had always been under the impression that the two-term president was the norm. It's not. It's not even common in the 'modern' (i.e. post-WWII) era: just five have managed to serve two full terms (Eisenhower, Reagan, G.W Bush, Clinton and Obama) - 7 served less than two terms.* Including all presidents, just 14 have served at least two full terms (FDR was elected 4x and died in office).
Grover Cleveland is the only elected president to serve non-consecutive terms, and it's worth noting that all prior to Eisenhower (the 34th President) were not limited by term limits (though eight died in office, thereby making them ineligible to run for re-election); 31 have served less than two full terms.
None of this is to say that Trump WON'T run for election or even that he won't win if he does, but eliminating those who died in office and served two full terms (a norm before it was a restriction) there were 24 could have run for re-election after losing the previous cycle, and only one succeeded. Most simply decided not to run again, though Teddy Roosevelt notably tried (and failed) in a 3rd-party bid.
*Kennedy was assasinated, LBJ served out the rest of his term plus one full term. Ditto for Truman (who replaced FDR). Nixon resigned leaving Ford to serve just under a term (he was the only president never elected to Prez or VP). Carter, Bush Sr, and Trump (so far) all served just one term.