Your challenge should you chose to accept it, is to have more Vietnam vets serve as president of the United States than WW2 vets. No POD's before Jan 1 1968
You can drag your idea out to 2020 if needed
Note for the purposes of this challenge we will consider anyone who was in the armed forces during the time of the conflict to be a "vet" they don't actually have to have seen combat, although bonus points will be issued if the Vietnam fellows have