Restraint of Executive In Governing Nation Act of 2020 or the REIGN Act of 2020 This bill requires the President to disclose to Congress presidential emergency action documents within a specified time frame. Such documents may include draft executive orders, proclamations, and messages to Congress prepared in advance of anticipated emergencies. Specifically, the President shall submit to Congress (1) any such document not later than 30 days after the conclusion of the process for approval, adoption, or revision; and (2) all such documents in existence before this bill's enactment date not later than 15 days after such date.