When a baby is born, we do not know who this precious life will become.

We cannot nuzzle that soft hair and divine a doctor or a ditch digger. Those impossibly tiny fingers curled into the tightest clench might belong to an artist or an assassin. The hospital can test for blood type or birth defect, but not for honesty or fraud, gentleness or violence.

All we can do is cradle this new life, give it love, promise it the world and hope for the best.

What we can know is whether or not that baby is a U.S. citizen. It is a status that might be due to the parents’ position. It might be due to geography. I am an American not just because I was born to a farm boy turned Marine and a city girl from Philadelphia, but because it happened in a Minnesota hospital.

It is the baptismal gift of the Constitution. Lady Liberty stood as godmother, making a promise to the tired, the poor and huddled masses yearning to breathe free. Their children, by virtue of taking that first breath on U.S. soil, would be Americans.

This is not something that happens in every country. America is not alone, but just a few dozen nations are so egalitarian. Most are in the Western Hemisphere. It is the New World where people saw opportunity to reinvent themselves and build new families.

In much of the world, citizenship is not tied to the place of birth but to bloodline, to status, to the paperwork of parents.

That simplicity is now at the center of a political fight.

On the first day of his second term, President Donald Trump signed an executive order to redefine citizenship, moving it from an unrestricted right to a conditional inheritance. That order has been batted down repeatedly by judges. On Wednesday, the issue was argued before the U.S. Supreme Court.

Supporters say it is about enforcing immigration law and preventing abuse of the system.

We don’t know how that will play out. In recent years, the court under Chief Justice John Roberts has taken distinct swings at pillars believed to be well-established law.

But if previous decisions have affected what it means to control your body or what it means to be president, this case could shake the foundations of what we are. It will decide what it means to be an American.

If birthright citizenship is ripped out of the Constitution by the roots, what will it affect?

Everything that follows.

It may seem it won’t affect you unless you aren’t an American — or unless you are the child of someone who isn’t an American. That is shortsighted.

Citizenship affects that newborn baby from the very beginning, with a birth certificate and a Social Security number. It can impact health coverage and access to daycare. What about school? What about college? Then there is getting a job, going into the military, getting married, traveling overseas.

Now take all of those things affecting one child and multiply them across every child — and every parent who would have to prove their own lineage to justify that child’s citizenship.

Working forward, it could pinball through every hospital, every school, every employer.

Working backward, it could take us to darker places in our history. That is how we locked Japanese citizens in camps, said “No Irish need apply,” and decided one drop of Black blood made you eligible for sale in the public square.

We don’t want to return to those uglier corners of our past. We don’t have to. We don’t need to judge our newest lives, weighing whether they merit the gift of admission into the flock.

Birthright citizenship is not uniquely American. But it is — and has been — intrinsically American.