You may like the New York Times quote, mentioned here.
**While “old enough to fight, old enough to vote” was one of the catch-phrases of the 1960s, the sentiment behind it had been expressed decades earlier during both World War II and the Korean War. But for many years there was opposition to lowering the voting age, including from The New York Times, which repeatedly argued against it. “The requirements for a good soldier and for a good voter are not the same,” said a 1967 Times editorial. “For the soldier, youthful enthusiasm and physical endurance are of primary importance; for the voter, maturity of judgment far outweighs other qualifications.”
Not any more. Even 98.6 is optional these days.
(Thanks for the reference, though!)