Subsequent work
He joined the Brookings Institution as a visiting fellow in September 2014. He became a senior fellow in their Governance Studies program and is the project chair of a research initiative on reducing corruption. At Brookings Eisen has contributed to reports on open government, the emoluments clause, presidential obstruction of justice, and anti-corruption efforts in the natural resource sector.
A prolific writer, he often contributes op-ed pieces to The New York Times, The Washington Post, Politico, USA Today, and other national publications.
From 2016 to 2019, Eisen served as chair of the board and co-counsel on litigation matters for CREW, including emoluments cases in New York and Maryland federal courts (CREW v. Trump and D.C. and Maryland v. Trump, respectively).
In 2017, Eisen was named number 11 on the Politico 50 list of thinkers shaping American politics. Eisen has also been named to the Forward 50 list of American Jews.
In September 2018, Crown published Eisen's The Last Palace: Europe's Turbulent Century in Five Lives and One Legendary House. It is a sweeping history of 1918 to 2018 as seen through the windows of the Villa Petschek, a Prague palace built by Jewish businessman Otto Petschek after World War I, occupied by the Nazis later, and then the residence the American ambassador in Prague during his term of office.
In February 2019, Eisen was appointed consultant to the United States House Committee on the Judiciary. He assisted the committee on oversight matters related to the Department of Justice, including impeachment, and other oversight and policy issues within the committee's jurisdiction. A columnist at The Washington Post called Eisen a "critical force in building the case for impeachment." Eisen later wrote a book about his time as special counsel.
He edited "Democracy's Defenders: U.S. Embassy Prague, the Fall of Communism in Czechoslovakia, and Its Aftermath" (2020) and authored "A Case for the American People: The United States v. Donald J. Trump" (2020).
With Colby Galliher, Eisen co-authored a book entitled, Overcoming Trumpery, which was published by Brookings Institution Press in 2022.
Eisen was a co-founder of the States United Democracy Center in 2021, and in his States United capacity, he signed a bar complaint against John C. Eastman and an ethics complaint filed against Jenna Ellis for their roles in undermining the 2020 election results. He served as co-counsel on an amicus brief filed in opposition to Lindsey Graham's motion to quash a subpoena in the Fulton County Special Grand Jury investigation of attempts to overturn the 2020 election results in Georgia. Eisen has co-written reports for States United including a guide to the Electoral College vote count and the January 6, 2021, meeting of Congress.
With his States United co-founders, Joanna Lydgate and Christine Todd Whitman, Eisen was a winner of the 2022 Brown Democracy Medal, given by the McCourtney Institute for Democracy at Pennsylvania State University. Eisen departed States United in early 2024.
In January 2025, Eisen and columnist Jen Rubin began authoring a Substack publication entitled The Contrarian. Along with the articles posted to the publication, he has posted brief videos to the newsletter to provide the readers with breaking news regarding litigation as it progresses and to share insights into the processes.