You've only taken half of the statement, it was:
> Foetuses are disputably citizens and people
Citizens is one part, people is the other. Whether a foetus is a person, whether it has constitutional personhood, was argued by Texas in the original Roe v Wade case. You may also note that the difference between person and citizen has been debated many times before in constitutional law. From [1]:
> Thirty years ago, Bickel made a statement about the relationship between citizenship and personhood in American constitutional law that is well known among scholars of immigration and citizenship. He said: “It has always been easier, it always will be easier, to think of someone as a noncitizen than to decide that he is a nonperson.”
> What is expressed here is both a descriptive and normative claim about the significance of the category of citizenship in our constitutional system. Bickel argued that, as a historical matter, the Constitution has never set much stock by the category of citizenship; that one of the most disastrous aspects of Dred Scott was that it treated the denial of rights to slaves and free blacks as turning on their lack of citizenship; that the framers of the Fourteenth Amendment came close to entrenching this mistake, constitutionally, via passage of the privileges or immunities clause of section 1, which might have appeared to make rights contingent upon citizenship; but that, in the end (by way of Slaughterhouse,7 which eviscerated the clause), “innocence was restored.” And Bickel concludes by expressing satisfaction with this state of affairs: “I find it gratifying … that we live under a Constitution to which the concept of citizenship matters very little.”
In important ways, Bickel is descriptively right. True, citizenship status is still quite significant in a variety of settings, and conflicts between citizenship- and personhood-based groundings of rights persist in various contexts. Still, for a great many purposes, the “right to have rights” is not contingent on the possession of citizenship status. In the international arena, it is largely persons who are the subjects of human rights
[1] https://academic.oup.com/icon/article/8/1/9/682631