[browardchad]

Both cases were argued on the merits of petitioners’ equal protection claims. (Not at issue here.)

Neither of the plaintiffs were granted citizenship.

Scalia, and Thomas, chose to re-iterate, and emphasize, the Court's stance on non-interference with the delegated powers of Congress to define citizenship.

[philman_36]

Scalia, and Thomas, chose to re-iterate, and emphasize, the Court's stance on non-interference with the delegated powers of Congress to define citizenship.
That's right. And Congress had already defined how citizenship was defined for children born out of wedlock.
From the Opinion of the Court on the case you reference...
As an individual seeking citizenship under §1409(a) must meet all of its preconditions, the failure to satisfy §1409(a)(4) renders Nguyen ineligible for citizenship.

USC TITLE 8, CHAPTER 12, SUBCHAPTER III, Part I—Nationality at Birth and Collective Naturalization
§ 1409. Children born out of wedlock