Harvard Law Today article:

HLT: Former President Trump has said he will assert executive privilege to prevent records related to the January 6 attack on the Capitol being turned over to Congress. Can he do that?

Eggleston: The law is actually fairly clear on this, although there’s always the issue of whether this new Supreme Court would follow the pretty settled law or not. So, let me give you two answers, the first administrative and the second legal. First, neither the current president nor the prior president has physical custody of the materials from the prior presidents. All of these materials are stored at the National Archives. I dealt with this as the last White House counsel for Obama, when we had the enormous processes of transferring our data out of the White House and to the Archives. If there is a request for what would otherwise be privileged material regarding a prior presidency, representatives of the prior president are supposed to consult with representatives of the current president, and then the current president decides.

When I was White House counsel, that happened from time to time with regard to communications out of the George W. Bush White House. My office would consult with the person that President Bush had designated to represent him for this purpose. During my time as White House counsel, there was never an objection from the prior president to releasing those materials. So, we never actually had to test to the limits of the law.

Separately, there’s a Supreme Court case called Nixon v. General Services Administration, the agency that had possession of the records of former President Nixon. Congress had passed a law to allow the GSA to seize and preserve all President Nixon’s presidential records. President Nixon sued, claiming the act was unconstitutional. The Supreme Court upheld the law and basically decided that the current president is the right person to make judgments about the assertion of executive privilege. That’s because under our system, the authority attaches to the office, not the human. President Biden has this power because he’s president, not because he’s Joe Biden. And when President Trump was in office, he had the power because he was President Trump, not because he was Donald Trump. So, I think the law is pretty well settled. But again, we have many years later a very new Supreme Court.