Sorry, maybe I'm misunderstanding what you mean, but isn't Obama an example of a president who thought (or at least said he thought) we should improve things somewhat? I definitely remember thinking "oh maybe things will improve once he's in office!". They didn't, of course, and I was a sucker for ever thinking they would. But still, it seems to me that Obama did exactly what AOC would do: promise that things will improve slightly if she's elected and then be unable (or unwilling) to actually change anything