The Justice Department on Thursday made public a series of internal memos that the Trump administration has relied on to justify its defiance of congressional subpoenas related to the impeachment inquiry.
The memos, written by legal advisers in the department's Office of Legal Counsel (OLC), date as far back as the Nixon administration and supply legal arguments for a broad reading of presidential power in the face of congressional oversight.
The OLC reportedly published the opinions in response to a request from House Democrats. The OLC cited the memos in a May OLC opinion that gave legal justifications for blocking the congressional subpoena against McGahn.
One of the newly released OLC memos, written in 1982 by Assistant Attorney General Ted Olson, is titled "History of Refusals by Executive Branch Officials to Provide Information Demanded by Congress."
The opinion from Olson traces historical examples since the country's founding where presidents ordered the withholding of information in the name of executive privilege. It cites instances from George Washington and Thomas Jefferson, through the Civil War and Reconstruction-era administrations of Abraham Lincoln and Andrew Johnson, and continues through the early years of the Reagan administration.
"The memorandum seeks to show that presidentially mandated refusals to disclose information to Congress " though infrequent " are by no means unprecedented acts of this or any other administration," the opinion states.
Another OLC opinion from 1982 was requested by then-Associate Attorney General Rudy Giuliani, who is now Trump's personal attorney. That memo, also written by Olson, explained how executive privilege applies when Congress requests testimony from close presidential advisers.
OLC opinions are generally considered binding on the executive branch, but courts are not required to treat them as legal authorities.