The case that may determine if former White House Counsel Don McGahn must testify before Congress – about whether President Trump obstructed justice during the Mueller investigation – is being argued on appeal tomorrow, January 3rd. And, three other cases concerning requests for President Trump’s financial records – issued by Congress and, separately, by a New York State grand jury – will be heard by the Supreme Court in early 2020. All of these cases involve subpoenas – written orders compelling an individual or organization to produce evidence or to testify – and raise important questions about the power of Congress and the states to investigate the president and his aides. Guests Steve Vladeck of the University of Texas School of Law and Andy Grewal of Iowa Law join host Jeffrey Rosen to explain all four cases: These three cases will be heard by the Supreme Court in March 2020: Trump v. Mazars: The House Committee on Oversight and Reform issued a subpoena requesting that President Trump’s accounting firm Mazars USA turn over financial records of President Trump and several of his business entities. The committee states that it's investigating whether and how to legislate on presidential financial disclosure requirements. The U.S. Court of Appeals for the D.C. Circuit ruled that the committee’s subpoena is valid. Trump v. Deutsche Bank: The House Committee on Financial Services and the House Intelligence Committee issued subpoenas requesting that President Trump’s creditors, Deutsche Bank and Capital One, release documents related to President Trump’s, his family’s, and his business’s finances. The committees state that they’re investigating whether and how to legislate on the practices of financial institutions and potential presidential conflicts of interest. The U.S. Court of Appeals for the Second Circuit upheld the subpoenas. In this case and Mazars, the Trump administration is arguing (among other things) that the subpoenas exceed the committees’ powers and do not serve a “legitimate legislative interest.” Trump v. Vance: Cyrus Vance, district attorney of the County of New York, issued a state of New York grand jury subpoena requesting nearly 10 years’ worth of the president’s financial papers and his tax returns for an inquiry into whether the President or his businesses violated New York law. The U.S. Court of Appeals for the Second Circuit upheld the subpoenas. This case differs from the other two because the subpoena was issued by a state, not federal, authority. The McGahn case 4.Committee on the Judiciary, U.S. House of Representatives v. Donald F. McGahn II: The House Judiciary Committee issued a subpoena calling for former White House Counsel Don McGahn to testify before the committee on whether President Trump obstructed justice in Special Counsel Robert S. Mueller III’s investigation of Russian interference in the 2016 U.S. election. U.S. District Judge Ketanji Jackson ruled that McGahn must testify, and the Trump administration’s appeal of that decision will be heard by the U.S. Court of Appeals for the District of Columbia tomorrow. Questions or comments about the podcast? Email us at podcast@constitutioncenter.org.