Gov. Gavin Newsom on Wednesday is expected to announce a lawsuit arguing that President Trump lacks the authority to enact the international tariffs without the support of Congress.

California Governor Gavin Newsom said his state is suing to halt Donald Trump’s tariffs, setting up a high-stakes legal challenge to the president’s landmark effort to overhaul global trade. The state will file a complaint Wednesday in San Francisco federal court challenging Trump’s use of emergency powers to enact broad tariffs against Mexico,

What he can actually do, I think, is pretty limited,” said Sean Randolph, senior director of the Council Economic Institute.