Legal experts were surprised by the judge's decision to appoint an official to review the documents.
The FBI's investigation into the former president's decision to remove government records, including highly classified information, to his home in Florida could be delayed.
Cannon's ruling was picked apart by attorneys and former federal officials who focused on her view that Trump may be able to assert executive privilege over some of the records.
Executive privilege is a legal concept allowing presidents to shield records of private deliberations with advisers from Congress and courts but has never been used before by an ex-president to shield records from the current executive branch.
The Biden administration has declined to assert privilege over any of the material Trump took with him to Mar-a-Lago, despite the fact that the current government owns all government records.
Bill Barr, who served as attorney general under Trump, said he didn't think a special master was necessary.
"If the documents are subject to executive privilege they involve official deliberations about executive actions and they belong to the government."
The Justice Department is currently conducting a criminal investigation into the handling of the records.
The New York Times quoted a constitutional expert as saying that a former president could shield his or her communications from the executive branch.
They wouldn't be able to do it in the context of a criminal investigation, and they wouldn't be able to do it after the material has been seized.
The logic of appointing a master to review the material was questioned by others. A special master is usually used to screen out material that is protected by attorney-client privilege.
She tried to stop the Exec Branch from using the materials, but the govt already reviewed them. NealKatyal was an acting attorney general in the Obama administration.
Cannon was confirmed by the Senate in 2020 and she said that the Supreme Court had not excluded the possibility of former presidents asserting executive privilege over a current government.
Cannon said that the Supreme Court did not rule out the possibility of a former president defeating an incumbent president.
The special master will review the records.
Abbott's decision is expected to be appealed by the justice department.