What must Congress establish to subpoena the President's personal records?

To subpoena the President's personal records, Congress must demonstrate a legitimate legislative purpose. This principle is rooted in the separation of powers and the checks and balances established by the Constitution.

When Congress seeks to compel testimony or demand documents from the President, it must show that the subpoena is tied to a specific legislative function, such as investigating matters pertinent to a potential law or the oversight of the executive branch. The requirement for a legitimate legislative purpose ensures that such actions do not become tools for political vendettas or harassment.

Other options, like a valid executive order or a joint resolution of both houses, do not meet the constitutional requirements to validly issue a subpoena to the President. Similarly, a two-thirds majority vote is not necessary for issuing subpoenas, as subpoenas are typically issued by committees with appropriate jurisdiction rather than requiring a full House or Senate vote. Therefore, a legitimate legislative purpose is the cornerstone requirement that provides Congress the authority to act in this capacity.