"politics"

Next in line are still elderly but they've been spending their whole life building up to this so they aren't going to put some young whippersnapper in charge and undo the years of bribery, corruption and arse-kissing that got them to where they are

The sitting president is the leader of his party. That's the rule. He's a sitting president, he has to get someone else to run, preferably WAY before now, but that looks like ''I'm a bad president'' which usually throws the election to the other party.

In reality, the president isn't running the country solo, you're voting for administrative appointments. We know who Trump will appoint, out of the two I'll stick with the Biden admin.