California’s governor and attorney general plan to sue President Donald Trump on Wednesday to try to stop his flurry of tariffs, accusing the president of taking unlawful action to escalate a global trade war that has caused “immediate and irreparable harm” to the state’s economy.

The lawsuit will be the largest legal challenge yet to Trump’s trade policies. It will be filed Wednesday in federal court in California by Gov. Gavin Newsom and state Attorney General Rob Bonta, both Democrats.

California is the largest importer and second-largest exporter among the states, and its economy is bigger than those of all but four countries. Mexico, Canada and China are the state’s top three trading partners, and its massive agricultural sector exports products around the world.

Trump’s tariffs are upending global trade. He imposed a 10% tariff on nearly all imports from most of the world, and his escalating tariffs with China have reached 145%.

Newsom Said Tariffs Cost the State Billions

Newsom said the tariffs had already cost the state billions of dollars in inflated costs and supply-chain disruptions, and that he was particularly concerned about the vulnerability of California farmers to the retaliatory trade policies of other countries.

The lawsuit, which will be filed in the U.S. District Court for the Northern District of California, asks that the tariffs be declared unlawful and that federal agents be stopped from enforcing them. It focuses on Trump’s use of a 1977 law to impose the tariffs. The law, known as the International Emergency Economic Powers Act, generally grants the president sweeping powers during an economic emergency.

Trump has claimed that an influx of illegal drugs from China constitutes a “national emergency” that requires “immediate action.” But California officials argue that the Constitution expressly gives the authority to impose tariffs to Congress, not to the president. State officials also say that while the economic powers law specifies many actions a president can take in an emergency, “tariffs aren’t one of them.”

“We’re standing up for American families who can’t afford to let the chaos continue,” Newsom said in a statement.

The implementation of the president’s tariffs, Bonta said, was “not only deeply troubling, it’s illegal.”

On Monday, a nonpartisan legal advocacy group, the Liberty Justice Center, asked the U.S. Court of International Trade to block the tariffs on behalf of five small U.S. businesses that say they will be hurt by them. Earlier this month, a conservative legal group, the New Civil Liberties Alliance, sued in federal court in Florida, arguing that Trump had overstepped his legal authority.

—

This article originally appeared in The New York Times.

By Shawn Hubler/Kenny Holston
c. 2025 The New York Times Company