I'm new to this forum and haven't read anything that cites Mark Winegardner's 2004 novel "The Godfather Returns", which fills in spaces in the Corleone family's timeline.

In this book, it is revealed that Don Michael, with his father Vito as consigliere, had envisioned a plan in which Tom Hagen would make an unsuccessful run at a Senate seat which would, in turn, legitimize a state cabinet appointment. This would then lead to an easy run for governor of Nevada for Hagen.