Maybe I'm just being overly cynical, but I have a hard time believing that any of these MOCs (particularly the senators) have anything to do with the selection process. They almost never attend any of the interviews and I just can't see them taking the time pouring over SAT scores, reading recommendations and then doing a comparison. At the most, they are probably briefed on the candidates; yet, probably not even that. Consequently, I'm convinced that the Service Academy Coordinator is the one making the final decision; or maybe some low-level staff members. And, even with that, it's probably a collateral responsibility for them. The slate of ten nominees goes across the MOC's desk and he/she signs their signature to it.
I realize that some of the MOCs actually make phone calls to the nominees to congratulate them; but, that certainly does not mean that they had any deep involvement in selecting the candidate.
This is why I always advise candidates to be cognizant that all their dealings with the MOC's office - every phone call, every letter, every email, everything you submit - that the person with whom you are corresponding may very well be the person who ultimately decides your fate. Make life very easy for them. Do not think of them as the intermediary between you and the MOC. Think of them as the MOC!