Pretty much the only comparable parallel to the current imbecile in office, is Buchanan in 1861. He managed to alienate everyone with a completely ineffectual presidency, and was persona non grata across the spectrum, however, he had only ever pledged to run one term.
I do not believe there has ever been a situation where a President was forced not to run for re-election by his own party. Truman was technically grandfathered in to the 22nd Amendment and was talked out of running in 1952 due to low approvals, but had already served nearly 2 terms. Similar with LBJ but he too had a full term plus the remainder of JFK’s.
“I do not believe there has ever been a situation where a President was forced not to run for re-election by his own party.”
Does LBJ knocking off JFK count?
;-)