On Wednesday, Gov. Gavin Newsom and California Attorney General Rob Bonta filed a lawsuit in federal court challenging President Donald Trump’s use of emergency powers to enact broad-sweeping tariffs that hurt states, consumers, and businesses.

The lawsuit argues that President Trump lacks the authority to unilaterally impose tariffs through the International Economic Emergency Powers Act, creating immediate and irreparable harm to California, the largest economy, manufacturing, and agriculture state in the nation.

These tariffs have disrupted supply chains, inflated costs for the state and Californians, and inflicted billions in damages on California’s economy, the fifth largest in the world.

“President Trump’s unlawful tariffs are wreaking chaos on California families, businesses, and our economy — driving up prices and threatening jobs. We’re standing up for American families who can’t afford to let the chaos continue,” said Newsom.

“The president’s chaotic and haphazard implementation of tariffs is not only deeply troubling, it’s illegal,” said Bonta. “As the fifth largest economy in the world, California understands global trade policy is not just a game. Californians are bracing for fallout from the impact of the President’s choices — from farmers in the Central Valley, to small businesses in Sacramento, and worried families at the kitchen table — this game the President is playing has very real consequences for Californians across our state. I am proud to go to bat alongside Governor Newsom to fight for California’s vibrant economy, businesses, and residents.”

The lawsuit, filed in the United States District Court for the Northern District of California, requests the court to declare the tariffs imposed by President Trump void and enjoin their implementation.

Since early February, the Trump Administration has issued over a dozen executive orders under the International Emergency Economic Powers Act of 1977, or IEEPA, to impose tariffs that have sent shockwaves through financial markets, businesses, and consumers in every corner of the globe.

The IEEPA gives the president authority to take certain actions if he declares a national emergency in response to a foreign national security, foreign policy, or economic threat. The law, which was enacted by Congress in 1977, specifies many different actions the president can take, but tariffs aren’t one of them. In fact, this is the first time a president has attempted to rely on this law to impose tariffs.

Claiming authority under the IEEPA, President Trump has issued multiple executive orders to impose, pause, re-start, and modify 25% tariffs on Mexico and Canada and a universal 10% tariff on every other U.S. trading partner.

The president’s actions have goaded China into a full-blown trade war, with tariffs reaching 145% on Chinese goods, and China imposing reciprocal 125% tariffs on U.S. goods.

Additionally, President Trump has imposed individualized reciprocal tariffs of up to 50% on nearly 90 specific countries; they are currently paused for 90 days before going into effect. Once the 90-day “pause” expires, the harm will only compound further. And new tariffs are being contemplated or announced nearly every day.

To justify his tariffs, the president has declared national emergencies and extended prior declared emergencies beyond the bounds of reason. But with or without emergencies, the president does not have the power to levy tariffs under the IEEPA, according to Bonta and Newsom.

In the lawsuit filed Wednesday, Bonta and Newsom challenge the president’s use of the IEEPA to levy those tariffs, arguing that the IEEPA does not authorize the president to impose these tariffs.

The emergency tariffs challenged under the lawsuit are projected to, at a minimum, shrink the U.S. economy by $100 billion annually, increase inflation by 1.3%, and cost the average American family $2,100.

The economic impact of the president’s tariffs could have resounding impacts on California’s economy, budget and consumers, Bonta and Newsom argue. California is a significant and frequent purchaser of goods impacted by the tariffs and the projected increase in cost to the state is significant.

California’s gross domestic product was $3.9 trillion in 2023, making it 50% bigger than the GDP of the nation’s next-largest state, Texas. The state drives national economic growth and also sends over $83 billion more to the federal government than it receives in federal funding.

California is the leading agricultural producer in the country and is also the center for manufacturing output in the United States, with over 36,000 manufacturing firms employing over 1.1 million Californians.

The Golden State’s manufacturing firms have created new industries and supplied the world with manufactured goods spanning aerospace, computers and electronics, and, most recently, zero-emission vehicles.

California engaged in nearly $675 billion in two-way trade in 2024, supporting millions of jobs throughout the state. California’s economy and workers rely heavily on this trade activity, particularly with Mexico, Canada, and China — the state’s top three trade partners. Over 40% of California imports come from these countries, totaling $203 billion of the more than $491 billion in goods imported by California in 2024.

These countries are also California’s top three export destinations, buying nearly $67 billion in California exports, which was over one-third of the state’s $183 billion in exported goods in 2024.

The lawsuit invokes the U.S. Supreme Court’s major questions doctrine, which holds that in novel matters of vast economic and political significance, federal agencies and the executive branch must have clear and specific authorization from Congress.

In recent years, the court has applied this standard to strike down major initiatives, including President Obama’s Clean Power Plan and President Joe Biden’s student loan forgiveness program, ruling that novel executive actions with broad impacts on the national economy cannot rest on vague statutory authority.

The complaint filed Wednesday alleges that the Constitution expressly gives the authority to impose tariffs to Congress, not the president, and the IEEPA does not provide the required congressional authorization for President Trump to impose tariffs — Congress enacted the IEEPA to limit Presidential authority and to prevent Presidential abuse of power — not to give the President these powers.

The complaint asks the court to declare that tariff orders made under the purported authority of the IEEPA are unlawful and void and to halt DHS and CPB from implementing and enforcing these orders.