Lincoln consistently scores top or at least top 3 in every ranking of US presidents (e.g.). This high standing has long puzzled me. After all, this is the leader who presided over a long brutal civil war that killed 620,000 of his own people. For context, as a percentage of the population, that is more American lives than all other presidents put together have managed to expend in all America's other wars. On the face of it, that is a massive failure of statesmanship, however competent Lincoln was at running the war itself. The usual response is that the war was a necessary sacrifice to end the supreme evil of slavery. I do not find this convincing.
Note that I do not claim that Lincoln was a terrible president (there have certainly been many worse presidents). I only question whether the case for his greatness survives rigorous scrutiny, especially when you push beyond the commonly repeated platitudes.