Letter Brief filing Supplemental Authority, from Seth Barrett Tillman and the Judicial Education Project as Amici Curiae in Support of the Defendant, District of Columbia & State of Maryland v. Donald J. Trump, in his official capacity as President of the United States of America, Civ. A. No. 8:17-cv-01596-PJM (D. Md. Mar. 19, 2018) (Messitte, J.) (filed by Josh Blackman et al.), ECF No. 97.