General Discussion

The concern tends to be only when the Senator is from a state where the governor is the other party and has no restrictions on who he can nominate.

A plus is that Senators are very likely to easily confirm fellow Senators. Look how easily Rubio was confirmed versus almost all other Trump nominations.

On lack of relevant background alone, if Mullin were not a Senator, I doubt this would even be close. His story that as a Senator he was sent to Navy training and then on a covert mission where he can't say where he went is so strange he should have been rejected when he doubled down on that story. That he wouldn't apologize for his comment on Paul and his other comment on punching people in the face sometimes being needed shows he does not have the temperament to head the organization.

Ignoring the separation of power, if the CIA or another intelligence agency needed someone wouldn't they pick someone with military experience? I can think of NO advantage to an agency to the person being a Congressman.