Lower the voting age to include those who will be 18 for at least half of the next presidency

Many people will have to live as a legal adult for up to 4 years under a president in whose election they had no say. Lower the voting age for presidential elections to one of the following:
1] Those who will turn 18 on or before the middle day of the term of the president being voted upon
2] Those who will turn 16 before Jan. 1 after the election, shortly before next inauguration day)
3] Those who will be 16 on or before inauguration day
The voting age is 18 to begin with because that is when men must sign up for the draft, allowing them to vote. Some may have to fight in a war they didn't want due to a president they didn't chose (Turned 18 shortly after election). This will ensure that those becoming legal adults will have a say in the president under whom they will be legal adults.