In two prior postings (here and here), I listed flaws in the constitutional arguments of opponents of birthright citizenship for children of aliens living here illegally.
For children to be American citizens by virtue of the Fourteenth Amendment, they must be born within American territory and they (or rather their parents) must be “subject to the jurisdiction” of the United States. Those opposing birthright citizenship hurt their own case by basing it principally on the claim that visiting foreigners never qualify as “subject to the jurisdiction.”
The problems with that claim are:
The congressional debates cited to support it represent only weak evidence of meaning and are ambiguous on the subject, at best.
Before adoption of the Fourteenth Amendment, many (probably most, perhaps all) African-American were legally foreigners, so the Amendment had to include foreigners to achieve its purpose of extending citizenship to them.
The U.S. Supreme Court has decided twice that the meaning of “subject to the jurisdiction” is governed by the English common law doctrine of allegiance. That doctrine grants local citizenship to the children of most visiting foreigners.
I do not have a dog in this hunt. But if I were legal counsel for opponents of birthright citizenship, I would take their legal argument in an entirely different direction. And I would try to square my case with precedent instead of arguing that precedent should be disregarded.