My dad was a high functioning alcoholic nearly his entire adult life, and of all the things I admire about him, his ability and determination to work through it and eventually kick alcohol late in his life is one of the most significant.
I have read a bit about Grant, and while I think some of the issues about his drinking are a bit overblown as sometimes happens to people who make a lot of enemies, especially enemies that are the result of performance comparison where the person doing the exaggerating is on the inferior side.
But it is also clear that Grant did have an issue with alcohol, so he battled it.
In my opinion, it is difficult not to be impressed buy a guy who just a few years earlier had been sleeping under stairs wearing all his clothes.
That is quite a jump to make...from that to leading General to the Presidency.
I have always felt his biggest weakness was that he trusted people he shouldn’t have. He had what we call “loyalty issues”. I fall prey to that myself, giving people far too much rope who end up to not have been deserving of such loyalty.
I think President Trump suffered from this as well.