"The invariable and basic rules of Islamic law are only those prescribed in the Shariah, Khan writes. All other juridical works must always be subordinated to the Shariah.
Does "all" really mean all there?
He explains that Sharia is derived from the Quran and Sunnah, and that the Quran is the absolute authority from which springs the very conception of legality and every legal obligation.
Is he addressing all legal systems, or only Sharia?
It'll probably take a few more days before there has been a fairly thorough review of his past writings and statements.
The key question will be, does he believe the short and simple Islamic concept of law in general: "No man's law above Allah's law." Some columnists think he believes precisely that.
So, to answer your question, where it says "all," it means "all", including the US Constitution, English common law, and common law as practiced in the sate courts of the US.
I'm open minded, but before I subscribe to a believe that Khan advocates Sharia be substituted for US law, I'd like to see something other than a scholarly dissection of Sharia followed by inference - that's CNN methodology, and it flat out doesn't work.