Constitutional control and limits of the executive's trade policy in a comparative perspective: Spain-United States

Abstract

This article analyzes, from a comparative legal perspective, the mechanisms of parliamentary and judicial oversight of state trade policy in Spain and the United States, with particular attention to the constitutional limits on executive power in matters of foreign economic action. Starting from the constitutional framework of both systems, the study examines the distribution of powers between the legislative and executive branches in international trade, as well as the role of the courts as guarantors of institutional balance. In the United States, the article addresses the interpretation of the Trade Clause of Article I, Section 8 of the Constitution and the Supreme Court's oversight of broad delegations to the President regarding tariffs, especially in contexts of national emergency. In Spain, the article analyzes the integration of international treaties and European Union law into the constitutional system, the scope of Article 93 of the Spanish Constitution, and the role of the Constitutional Court as guarantor of constitutional supremacy against potential overreach by the Executive branch. This work combines a review of recent literature, jurisprudential analysis, and a functional comparative law approach, also proposing de lege ferenda reforms aimed at strengthening parliamentary intervention and the clarity of legislative delegations. The main conclusion argues that trade policy is an area particularly sensitive to executive expansion, but also a privileged space for reaffirming constitutional checks and balances and the democratic principle in consolidated democracies.