have historically been considered binding on the executive branch, unless they are overturned by the Attorney General or President. In 2009, Attorney General Eric Holder overturned an unpublished OLC opinion that had concluded that a D.C. voting rights bill pending in Congress was unconstitutional. Trump administration Early in the Trump administration, OLC approved Executive Order 13769 (referred to as the "travel ban" because it restricted entry from certain foreign countries which had Muslim-majority populations). Days later, Acting Attorney General Sally Yates announced that the Department of Justice would not defend the Order in court. Explaining her decision, Yates stated that OLC's review assessed only whether a "proposed Executive Order is lawful on its face and properly drafted," not outside evidence about the order's purposes or whether the policy of the order is "wise or just." Yates was fired later that day. Her successor as acting attorney general, Dana Boente, referenced OLC's analysis when he reversed her decision. The Executive Order was challenged in court, then superseded by subsequent Executive Orders and Presidential Proclamations. In a United States Senate hearing, Yates was asked whether she was aware of any past instance of an attorney general rejecting an executive order that had been approved by OLC. Yates testified that she was not aware of that ever happening, but that she was also not aware of a situation in which OLC failed to tell the attorney general about an executive order before it was issued. Barr letter In March 2019, the Mueller investigation delivered its final report to Attorney General Bill Barr. Even before reading the report, Barr had already made the decision to clear Trump of obstruction of justice. Upon receiving the report, Barr tasked the OLC with preparing a memorandum that would pretextually justify Barr's decision, instead of providing candid counsel. This memorandum was written in tandem with the Barr letter over the course of two days; the final version was signed by Steven Engel and Ed O'Callaghan. The D.C. Circuit held that the memo was not shielded from disclosure by the deliberative process privilege, because then-Attorney General Barr had already determined, by the time the memo was written, that DOJ would not charge Trump with a crime, making the memo akin to a "thought experiment." Whistleblower complaint In September 2019, Engel authored an OLC opinion that the Justice Department should not forward the Trump–Ukraine scandal whistleblower complaint to Congress. In