It has been speculated Abraham Lincoln was bipolar. Interestingly, Winston Churchill and General Patton too.
I don’t know about Lincoln and Churchill but I have known successful bi-polar people in business.
Their highs are so great ... they believe they can do anything and, by gosh, they can.
The smart ones simply hole up during their lows and re-emerge when the low is over.
Hard to do during a campaign though.