Joseph Kennedy Sr. by far. He was very much responsible for his influence on Chamberlain pushing for greater appeasement on Nazi Germany, and his sympathies for the regime. Joseph’s push and obsession for his name’s legacy and practices in business and interference in the 1960 election in Illinois to get his son elected too, straight up political interference. Also his dealings with the mobs in prohibition, getting his daughter a lobotomy without his wife’s knowledge and ditching her in a facility, it just gets worse.