When did Obama become a "brilliant constitutional lawyer?"
He taught classes at U. of Chicago while they provided him office space and a salary to write his book. He was already working on his political career in state politics. As best I know, he never tried a case as a lawyer, and certainly not a case based on a constitutional issue. He never authored any papers on constitutional law. He basically went from law school to law lecturing, while simultaneously doing community organizing and running for the state legislature.
That's the resume of a "brilliant constitutional lawyer?" Sheesh.