So? Just because a legislature sees fit to codify a Common Law precedent in a statute doesn't make the precedent any less valuable or binding.
They didn’t codify the precedent. The law says, “And the children of citizens of the United States, that may be born beyond sea, or out of the limits of the United States, shall be considered as natural born citizens ...” They aren’t saying these children ARE natural born citizens, which was the language Blackstone used in reference to English common law, “all children, born out of the kings ligeance, whose fathers were natural-born subjects, are now natural-born subjects themselves ...” The language in the 1790 naturalization act is softer, ‘considered as ...’ In 1795, the completely dropped the phrase natural born citizen: “the children of citizens of the United States born out of the limits and jurisdiction of the United States, shall be considered as citizens of the United States ...” The problem is that a naturalization act can’t technically create natural born citizens, and evidently someone recognized this and changed the language.