Actually I love the whole idea in that book: That those that make the decisions for others must show their service that they care about the others.
Only veterans voted. But you could only vote after you got out of the service. Notice though, that it wasnt all infantry...your service was geared to your ability. In Juans case, it was Mobile Infantry. when he sat down and made his decision to go career, he thought about why he joined in the first place. He wanted the right to vote. But he didnt really need to do that right away..because he voted with every drop he made on the enemy.
Its a great story. I still keep a copy in my nightstand. Ilike the fact that someone had the guts to bring it up in the topic.