The Supreme Court will rule today on President Donald Trump’s executive order attempting to end automatic birthright citizenship. Lower courts have universally rejected Trump’s first-day order, which would deny passports and other documents to children born to parents who are not citizens or green card holders.

That is the phrase, stuck in the middle of the first sentence of the first section of the 14th Amendment, that President Donald Trump is seeking to redefine as part of his campaign to overturn the more than century-old policy of birthright citizenship in ...