Is there any legal obligation to allow non-citizen parents to stay with their citizen children?

Question

Recently, there has been quite a bit of uproar in the news about the citizenship (or lack thereof) of illegal immigrants' children born in the United States.

Presuming that the courts decide that illegal immigrants' post-migration children are born subject to the jurisdiction of the United States, and therefore are citizens¹, is the government obligated to let citizens' non-citizen parents and siblings remain in the United States to accompany them?

Relative to the tags: I am interested in answers both for the federal government and the Texas government (provided law in the latter differs.)

^{1: I personally believe this is the proper interpretation, but I am not a lawyer.}

Answer 1

In the United States, no. Having a US citizen child does not prevent the alien parents being deported, if they are otherwise deportable. Here is some case law:

• Mendez v. Major (8th Circuit, 1965)
• Perdido v. Immigration Naturalization Service (5th Circuit, 1969)
• Enciso-Cardozo v. I.N.S. (2nd Circuit, 1974)
• Cervantes v. Immigration Naturalization Service (10th Circuit, 1974)
• Gonzalez-Cuevas v. I.N.S. (5th Circuit, 1975)
• Acosta v. Gaffney (3rd Circuit, 1977)
• Lee v. I. N. S (9th Circuit, 1977)
• Mamanee v. Immigration Naturalization Service (9th Circuit, 1977)

Answer 2

In Germany (most other EU jurisdictions are similar) this works very differently.

First, citizenship is not assigned by place of birth. So if two non-German citizens have a child born in Germany, this child will generally not get German citizenship unless there are other reasons to grant it.

On the other hand, if a non-German citizen has a minor child with German citizenship (for example if the other parent is a German citizen) this is a valid reason for granting German residence. The German keyword here is Familiennachzug. This is the relevant law; the reasoning is based on the German Grundgesetz (constitution) which has a rule stating that the family is under special protection of the state.

Answer 3

While US is - as usual - not a ratified signatory, the Convention on the Rights of the Child forbids this very explicitly (The US has signed the treaty but never ratified it).

1. States Parties shall ensure that a child shall not be separated from his or her parents against their will, except when competent authorities subject to judicial review determine, in accordance with applicable law and procedures, that such separation is necessary for the best interests of the child. Such determination may be necessary in a particular case such as one involving abuse or neglect of the child by the parents, or one where the parents are living separately and a decision must be made as to the child's place of residence.

This is the pertaining paragraph, including the exceptions to the rule. It is very explicit what are (topics of) valid exceptions and "we don't like em here" is very clearly not one of them.

Tl:dr: Under international law and human (childrens) rights, absolutely illegal.