Michigan Attorney General Bill Schuette yesterday asked a bankruptcy judge to block a subpoena that would force him to testify about why he wrote an opinion asserting that the Detroit Institute of Arts property cannot be sold in the city’s bankruptcy, the Detroit Free Press reported today. Bond insurer Syncora, which has aggressively fought Detroit’s bankruptcy, wants Schuette to deliver additional documents showing internal communications about the DIA opinion and testify at a deposition. The testimony and records would serve as fodder for Detroit’s bankruptcy plan confirmation trial — a massive hearing set to begin Aug. 14 that will determine the fate of the city’s restructuring plan. Schuette already turned over some documents showing his communication with DIA attorneys, but Syncora wants more. Bankruptcy Judge Steven Rhodes will determine whether the attorney general must testify and turn over records.