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David Zionts

David Zionts is an appellate litigator and international lawyer. He handles high-stakes appeals across a range of subject matters, and regularly works on transnational disputes and issues of international law that arise in both U.S. and international tribunals.

David has litigated matters of constitutional law, administrative law, and statutes including the Anti-Terrorism Act, Alien Tort Statute, and Foreign Sovereign Immunities Act. He has successfully represented companies, individuals, and foreign sovereigns before:

  • The Supreme Court of the United States, where he has represented clients at both merits and certiorari stages;
  • Federal and state courts of appeals, where David has argued numerous appeals;
  • District courts, where he has delivered arguments and crafted winning dispositive motions; and
  • International tribunals including the International Court of Justice, where David has argued as an advocate on behalf of a sovereign.

David also maintains an active pro bono practice, and has led litigation efforts in high-profile cases concerning immigration, transgender rights, reproductive rights, voting rights, and others.

Before joining the firm, David was a law clerk to Justice Stephen G. Breyer of the U.S. Supreme Court, and to Judge Merrick B. Garland of the U.S. Court of Appeals for the D.C. Circuit. He also served at the U.S. Department of State as special advisor to the Legal Adviser Harold Hongju Koh.

David has been named a Rising Star by both the National Law Journal and Law360.

Contact:Read more about David ZiontsEmail

UN General Assembly Adopts Resolution Requesting Advisory Opinion on States’ Obligations Concerning Climate Change

On March 29, 2023, the UN General Assembly (“UNGA”) adopted by consensus a resolution (A/77/L.58) requesting an advisory opinion from the International Court of Justice (“ICJ” or “Court”) on the obligations of states in respect of climate change. The resolution results from coordinated efforts by the Republic of Vanuatu, along with a “Core Group” of states, including Antigua and Barbuda, Bangladesh, Costa Rica, the Federated States of Micronesia, Morocco, Mozambique, New Zealand, Portugal, Samoa, Sierra Leone, Singapore, Uganda, and Viet Nam. The efforts of the Core Group drew on grassroots and civil society support, and the resolution was ultimately co-sponsored by more than 130 UN member states (although not the United States, Brazil, India, China, or Russia).

This marks the latest effort to ask international courts and tribunals to clarify the legal obligations of states in relation to climate change. In the last few months, similar requests for advisory opinions have been submitted to the International Tribunal for the Law of the Sea (“ITLOS”) and the Inter-American Court of Human Rights (“IACHR”).

Questions in the UNGA Resolution

The UNGA resolution observes that “as temperatures rise, impacts from climate and weather extremes […] will pose an ever-greater social, cultural, economic and environmental threat.” It asks the ICJ to issue its opinion on the following questions:

a) What are the obligations of States under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of greenhouse gases for States and for present and future generations;Continue Reading The World Court Set to Become the Latest Venue for Climate Change Jurisprudence

On Monday, November 7, the Supreme Court heard argument in Axon Enterprise, Inc. v. FTC and SEC v. Cochran to decide whether a party subject to an FTC or SEC administrative proceeding can simultaneously challenge the constitutionality of an administrative proceeding, or even of the agency itself, in federal district court rather than waiting for final agency action.  At least five Justices expressed some measure of support for the private parties’ arguments, which indicates that the Court may permit certain kinds of collateral constitutional attacks (e.g., due process and appointments clause claims) at the outset of administrative proceedings.

Although predicting the outcome of any case from the oral argument is extremely difficult, three Justices – Neil Gorsuch, Samuel Alito, and Clarence Thomas – expressed strong support for finding in Axon’s and Cochran’s favor. Through their questions, they implied that 28 U.S.C. Section 1331, which grants federal district courts “original jurisdiction of all civil actions arising under the Constitution of the United States,” provides a clear grant of jurisdiction over constitutional claims and neither the FTC Act nor the Securities Exchange Act of 1934 (“the Exchange Act”) could strip district courts of that jurisdiction. They also suggested that Free Enterprise Fund v. PCAOB requires a finding for the companies. In PCAOB, the Court held that a district court had jurisdiction to hear an appointments clause challenge to PCAOB’s structure despite the fact that the SEC had not yet issued a final order against Free Enterprise Fund.

Other justices appeared to favor the private parties, but not as overtly. Chief Justice John Roberts’s questions suggested that PCAOB may prove to be an insurmountable barrier to the government’s claims and that the availability of jurisdiction in other forums (i.e., the court of appeals) under the FTC Act and the Exchange Act clearly does not act as an implied removal of jurisdiction from Section 1331. Justice Brett Kavanaugh’s questions indicated that he believes that the issue may be decided solely by reference to the “wholly collateral” factor of the Thunder Basin test, which courts have used to guide determinations about when a party may bring an Article III challenge to agency proceedings before those proceedings have concluded. Thunder Basin Coal Co. v. Reich, 510 U.S. 200 (1994) (holding that the statutory review scheme of the Federal Mine Safety and Health Amendments Act of 1977 precludes a district court from exercising subject-matter jurisdiction over a pre-enforcement challenge to the Act). He stated that clarity, certainty, and speed counseled in favor of permitting district courts to hear constitutional claims.Continue Reading Supreme Court Considers Whether to Allow Early Constitutional Challenges to FTC and SEC Administrative Proceedings