U.S. Supreme Court turns away challenge to Trump steel tariffs

The U.S. Supreme Court on Monday turned away a challenge to President Donald Trump's tariffs on imported steel brought by an industry group that argued that a key part of the law under which he imposed the duties violates the U.S. Constitution. The justices declined to hear the American Institute for International Steel's appeal of a March ruling by the U.S. Court of International Trade that rejected the group's lawsuit. The institute is a pro-free trade group that represents steel importers and users of imported steel.

Trump imposed 25% tariffs on imported steel and 10% tariffs on imported aluminum in March 2018 based on national security grounds. Exemptions have been granted to Argentina, Australia, Brazil and South Korea in exchange for quotas. Canada and Mexico were exempted in May. In response, both countries lifted their retaliatory tariffs on the United States. The institute brought its lawsuit in June 2018, arguing that a section of the 1962 Trade Expansion Act, which allows presidents to impose tariffs based on national security, is unconstitutional because it delegates too much discretion to the president at the expense of Congress.

When the lower court rejected the challenge, the steel group chose to appeal directly to the Supreme Court instead of taking the case to a regional federal appeals court first. Two companies, steel trader Kurt Orban Partners and Sim-Tex LP, a oil pipe supplier, also joined the lawsuit.

Trump has rattled the world trade order by imposing unilateral tariffs to combat what he calls unfair trade practices by China, the European Union and other major trading partners of the United States. The bulk of Trump's tariffs have been aimed at China, covering $250 billion worth of Chinese goods so far. China and other countries have retaliated by imposing their own tariffs on U.S. goods.

(Reporting by Lawrence Hurley; Editing by Will Dunham)