That isn’t actually true.
The DoJ has a MEMO which argues that a president can’t fulfill his Duties if he is embroiled in a legal case.
It ignores #25thASec3 ratified (1967) 7 yrs before that Memo was originally written in 1973.
That MEMO is bullshit masquerading as legal doctrine.
Worse, the original DoJ Memo was written 7 YEARS after the #25thASec3 was #ratified.
Meaning the path for “if a POTUS is charged with a crime” ALREADY existed as part of the Constitution, when they dreamed that BS up, post Nixon.
It should be a crime that the Memo even exists.
They wouldn't be going to such extremes to hide his medical condition if it WASN'T something dire.
Previous presidencies have covered up such things, but in the modern era? Even George W signed his #25thASec3 and made VP Cheney an "acting POTUS" while George had sedation for a colonoscopy.
I would really, really like to see you post the results of a motion before the SCOTUS to re-consider their Immunity finding...
because the reasoning for it came directly from the 1973 + updated 2000 Memo from DOJ - which came years after the #25thASec3 which offers a BETTER answer.