On policy grounds this is a terrible idea. The best way to make new Americans is to give them a stake, from birth, in the success or failure of our country, and to give them a voice and a vote in our government. That's what birthright citizenship does. Observers from Alexis de Tocqueville onward have praised the easy terms by which immigrants can become Americans.
It’s a disputed question in some circles whether the Fourteenth Amendment actually confers birthright citizenship on all babies born here. I'm on the side saying that the plain meaning of the text is "Yes, obviously babies born here are Americans."
I understand that to our friends on the left, the constitution is a living document. I therefore must imagine they are ok with scrapping birthright citizenship. Because progress!
To the extent that the Constitution does have a determinate meaning, it can't be amended by presidential decree. That's just not how it works.