No doubt about it: complex relationship between Vito and Michael. As Michael said to Fredo in Havana: "It's not easy to be a son."

Both shared a desire to be considered "legitimate." Vito derived his legitimacy by providing "justice" to his fellow Sicilian immigrants. He bought politicians and judges, but the novel makes clear that at least some of that was based on personal favors exchanged between them. Michael simply assumed legitimacy because he regarded himself as no more corrupt than other powerful men. They got elected or appointed to high office and were considered legitimate, hence Michael was no different than them, and was "legitimate." No personal touch there.