I think maybe a more important question is why does he want to continue being president?
It is important to understand he has changed as a person.
He has found God and Country, and is not using the presidency to enrich himself for life like Obama and Clinton.
Secondly his ego and NY feistiness allows him to enjoy the battle.
The line in the sand will be when the mob attack his family which has started with the effort to ruin his marriage, rumblings of indictments against his sons, attacks against his business, and even attacking his young son barron.
Trump is at the age where his legacy is more important than anything. MAGA ain't a bad legacy. Maybe that is why he attacked OButthole so much because he did not like the direction America was going.