But is it really fair to compare what happens in the actual world with California’s alternate universe, where they’ve banned gravity for discriminating against differently-weighted people?
8-year olds have rights too, but we don't let them vote. Society does not deem it appropriate for them to decide their own destiny, much less that of others.
If you do not see the argument for universal suffrage except for people who have been tried before the law and condemned to a prison term, IMHO you've got a problem.
What this country is good at, is deciding whose rights need to be enforced, without too much regard to the consequences vis-a-vis other people (who one assumes also have rights). To quote the famous adage, your right to wave your fist ends where my nose begins.