Okay this is not meant to be cruel and I certainly don’t want the FBI or the Secret Service to come knocking on my door !
But what if President elect can not perform his duties and is not sworn in on January 20th Inauguration Day?
I will not list the reasons this could happen, but Covid-19 comes to mind !
PS I’m asking for a friend Nancy Pelosi !
VP becomes P
Correct. The Perfect Master thus held forth, wow, 40 years ago:
Wow! That is interesting … so if Biden/Harris should be in an accident together and perish the thought perish together then Nancy Pelosi would be the POTUS if her party approved, right?
Or whoever is elected Speaker when the new House convenes, yes. That will be before Inauguration Day on Jan. 20.
This is similar to the Season 4 Finale cliffhanger of the tv show The West Wing. The President’s daughter got kidnapped, and he was so distraught that in his opinion he was unable to govern effectively. In particular, he was afraid how he might respond to ransom demands. He decided to invoke the 25th Amendment (hence the title of the episode, “25”) so that the Acting President would make those decisions. Unfortunately, the VP had resigned a few weeks earlier because of a scandal. So the Speaker Of The House - who was from the other party - became Acting President.
Duh, I keep for getting the real-life example: Gerald Ford became President when Nixon resigned, because Nixon’s VP had already left in a scandal. Big difference was that in this case, all three were from the same party.
House Minority Leader Jerry Ford was appointed to fill Agnew’s VP vacancy and was the sitting VP when Nixon resigned eight months later. He was the first VP chosen to fill a vacancy in the post under the 25th Amendment (and his own VP Nelson Rockefeller was the second).
Ah, when a then-69 year old Ronald Reagan was thought to be entering the White House with one foot in the grave in account of his age. . .
Well, I guess that’s why I keep forgetting the real-life example! 
Thank you for the correction!
Only if the President elect is dead on Inauguration Day. If he is incapacitated, the Vice President would only act as President until the real President was capable of performing his duties.
It would be complicated. The usual procedure requires the concurrence of a majority of the cabinet, which would not exist with the President having never taken office. So Congress would have to pass a law authorizing an alternative body to determine the President is incapacitated.
On Inauguration Day, the Vice President elect would be sworn in as Vice President. Then she and this other body would officially notify the Speaker of the House and the President pro tempore of the Senate that the President is incapacitated and the Vice President would become the acting President.
Cabinet Secretaries are not automatically removed from office upon a change in Administration. While it’s customary for them to resign (knowing they’d be removed anyway), they are not required to do so.
Also, the 25th Amendment doesn’t refer to the “Cabinet” but rather “the principal officers of the executive departments.” Even if all Secretaries had resigned, each agency would still have a principle officer based on the order of succession for that agency.