I've always found it interesting that Jackson thought his stint prosecuting Nazi war criminals would be his stepping-stone to the Presidency. Didn't happen, and he ended up, seething and bitter, on the Supreme Court. Lots of folks in Washington considered Truman a lightweight (same reaction, I would imagine, as if Bush I had passed away and Quayle succeeded to the presidency) and none more so than Jackson, who responded by ruling against Truman in the steel seizure cases (and other cases too, if I remember correctly from law school).

Personal considerations can count for a lot more in the political and legal realms than most analyses credit them with.