What does the US Supreme Court IEEPA case mean for the future of tariffs - and executive power?

Jubilee G32, 11am -12 pm

To attend online, register here

Professor Hillman is one of the world’s foremost experts on the current US Supreme Court case on the legality of Trump’s reciprocal, or IEEPA, tariffs. She was a lead author on an amicus brief, with 191 Members of US Congress, on the illegality of these tariffs, which you can read here. Initial oral arguments suggest that the Court may rule against them, with implications for existing tariffs and Trump’s new trade ‘deals’, including with the UK. With the Supreme Court ruling due soon, Hillman will provide insights into what the case could mean, not only for tariffs but for Congress’s ability to constrain the powers of the US President. 

As well as acting as a former judge at the WTO Appellate Body, Professor Hillman has held appointments at the US Trade Representative and as a commissioner at the US International Trade Commission. She is currently a Professor of Law at Georgetown University and co-Chair of its Centre for Inclusive Trade and Development. 

By: Jessie Madrigal-Fletcher
Last updated: Friday, 23 January 2026