This is what he'd say:
"There is no excuse or explanation for my comment. I am so ashamed of my insult to the millions, living and dead, who have served and saved our liberty as enlisted service members that I am today resigning from the senate and retiring from public life. Any pension to which I am entitled will go to (name of charity serving enlisted service people). That is all I can do to demonstrate my shame. Thank you, and once again I apologise for what I said, and more for the fact that I thought it.