Nationalism. As Manifest Destiny was geared towards more of the individual people's growth (i.e go-getters) compared to Nationalism; the growth and advancement of the nation's people's as a whole.
Branch Rickey felt that his character was just as important as his baseball skills. Jackie Robinson was chosen to "break the color barrier" and he would need to be a strong individual and be able to avoid confrontation. He knew that Jackie Robinson would have to endure a lot of hostility and insults.
Because he was exiled by his country and anyone was a liberty to take his life if he returned. Anyone who was caught helping him was going to face consequences.
Voltaire Voltaire
French writer and philosopher
