At the age of 18, every American citizen is automatically eligible to vote.

Since it has become a partisan issue, with Democrats claiming that photo id is discriminatory to the poor, elderly, and minorities while Republicans counter that it is needed to combat voter fraud, with the main goal should be that everyone that can vote is able to vote, have every American citizen automatically eligible to vote on their 18th birthday. With today's technology why isn't every citizen automatically eligible to vote on their 18th birthday?