Suppose Trump asked the current archivist of the United States—appointed by President Obama in 2009—to destroy certain records, as he asked James Comey not to investigate Michael Flynn. Suppose the archivist refused, as Comey refused. Suppose Trump then fired the archivist, as fired Comey. Suppose Trump then told a television interviewer that he fired the archivist precisely because the archivist refused to destroy documents that might incriminate him—as he told Lester Holt that he fired Comey to shut down the Russia investigation.
If firing the FBI director to stop a prosecution falls within the president’s Article II powers, so then does firing the archivist to compel the destruction of documents. How then can Dershowitz insist that the president may not destroy evidence? By Dershowitz’s own reasoning, the president certainly can.