Will he promise to end the Selective Service System?
My sister found both of our grandfathers' draft registrations, from 1918. At that time they were 21 and 37 respectively. It was required to register up to the age of about 42.
The younger enlisted and served in combat in France. My father, father-in-law and my uncle served in WWII, including combat. I am being designated to hold my father's Purple Heart, since I served.
When more people served, more people had a stake and that made for a better citizenry and a better country.
People were also on a timeframe to grow up, because military service was adult in nature.