Did they count them in the census? If they considered them "persons" then they're entitled to representation. If they don't get counted then they're being denied representation.
What did they consider the "0 point" of a person's age, when they were first recognized as a person?
Again, you're conflating the privileges and immunities of citizens and the God-given rights of individual persons.
Again, all citizens are persons, but not all persons are citizens.
The framers of the Fourteenth Amendment understood this simple distinction perfectly.
Section. 1. All persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
A foreign visitor to our country doesn't have a right to vote or run for office. But, their rights to life, liberty and property are protected in each and every jurisdiction.