Surely it can't be approval ratings since you can't expect public to understand nuances behind the decisions and what the president actually has to be doing? It can't be just GDP because GDP might have been going up anyway? It can't be what the president is saying in public and how many of those facts are wrong since this doesn't mean what actual decisions the president is making.
For example the Bible has a lot of wisdom like: 'If a kingdom is divided against itself, that kingdom cannot stand.' This was already written some 2000 years ago and has been proven true over time.
So I would argue you could measure the amount of unity a leader tries to create.
That’s a nice one. Yet do you think then Hitler might be a good leader? (not a joke). He united the white German population in a time of great economic disarray - in both Germany and Europe. Maybe we should measure unity and cooperation with other countries? Global solidarity
Rather, he united the country because it was in an economic disarray :)
Number of his supporters arguing that objectively there's no such thing as a good president :-p
That’s probably a bad metric because his supporters love him.
It’s the swing voters making those kinds of comments because they want to vote for him but he’s done some dodgy things.
If you look at a basket of well-being measures as opposed to raw GDP it's hard to argue that Trump has done a good job.
Of course Covid has had a big effect. But there were many policy options for handling that, and Trump - and his far-right equivalents in other countries - reliably picked some of the least effective ones.
Regarding bankruptcies, unemployment, household debt Etc, Obama's first term would show really low score on these things, presuming that's all he had, almost none of it was caused by the actions taken by him during his presidency.
It is too soon to argue any of those measures.
You can’t take a single moment in time in the middle of a crisis to judge.
I like to give Trump as an example: everyone loves to blast him for being an idiot. Is he a good president? No. Is he good at the game, but most people totally miss what his game is? I claim, yes. It's unfortunate that he managed to play the US election system for his own purposes, but that doesn't mean he's just incompetent at everything. E.g. he's a rather good populist - that may not be a quality you like, but at that particular game he's not at all bad.