After all, Superman was an illegal immigrant — one of the 9.3 million estimated to be living in the United States today.
As those of us who recall Action Comics Annual #3 know, this is wrong. When a strange set of circumstances led to Superman becoming a candidate for president his immigration status was litigated with the Supreme Court determining that since he was transported to the planet earth in a kind of artificial womb, he’s actually a natural born citizen of the United States of America.
.... Some may say that because this was merely an alternate timeline, my observation is invalid. But the facts of Superman’s birth are the same in the “canonical” universe as in this branch of time, and the case of Uatu v. Lewis (1993, supra) firmly established that counterfactual legal precedents are binding on lower courts until explicitly overruled by the Supreme Court.
Update After further consultation, it seems that the birthing matrix concept is part of the "Man Of Steel" continuity that's since been superseded by "Superman: Birthright" which does, in fact, have Superman as an illegal immigrant.
But, but, but, all this garbage about 'Birthright' is totally irrelevant, because the whole thing was re-retconned after the Infinite Crisis series. The canonical account is now the 2010 Superman: Secret Origin story and everything else is now heresy.
My other hobby is theology, which has to do its retconning under a much more restrictive set of rules; the original frames must remain unaltered, but the deific significance of any element can be varied without limit.