In answer to ronrontaiwan and nawlins72, there have, indeed, been cases of American courts taking seriously claims by Muslims that sharia justified what they'd done.
More important here, though, is the fact that Muslim grievance organizations, such as CAIR, have immediately sued when states such as Oklahoma and Kansas have enacted these statutes or constitutional amendments. If they didn't have designs on imposing sharia on the American polity (something they've actually admitted, in other venues, is their aim) why would they object to such laws? Such laws would be irrelevant and not worth the time or resources to oppose them if they had no such designs.
Columnist Chapman occasionally has a useful point to make, but not on this subject.