The late, great Lawrence Auster had a fabulous write up on the subject of Birthright Citizenship not long before he died.
It is preserved here:The Truth About Birthright Citizenship
The summary page of all the discussions is here:The Birthright Citizenship Discussion at VFR
Everything here has been discussed before, and it's surprising that it's even controversial what Trump is doing, at least on the American Right.
It's not.
The most important reference in the article is the brief by Meese and Eastman:Brief of Amicus Curiae The Claremont Institute Center for Constitutional Jurisprudence In Support of Respondents
Larry also wrote The Path to National Suicide which explains how we got here, and he wrote it back when people didn't understand what was happening to us as a result of the Left's shenanigans.
The EO is probably a directive to the Federal Government to stop recognizing the children of illegal aliens as citizens for the purpose of issuing passports. There has been a long standing directive from the State Department to do so, absent any legal directive from the courts or the Congress - they just went ahead and did it. They may have some thin backing from Wong Kim Ark or even Plyler v. Doe, but not much. In any event, for the State Department, Trump definitely can change that, and in the long term, the Congress has authority to clarify the Fourteenth, they just haven't. There have been many bills to do so, all failing. But if we hold the Congress, I think that would not be the case.
And that is why we MUST hold the Congress in a week.
Larry Auster, a great, great man.