Supreme Court ruling throws Trump administration's tariff strategy into flux. What it means for global trade, U.S. economy

Shipping containers at the port of Oakland following the Supreme Court's ruling that Trump had exceeded his authority when he imposed tariffs, in Oakland, California, U.S., February 23, 2026.Carlos Barria | ReutersThe Supreme Court struck down U.S. President Donald Trump's tariffs on Friday, but the trade tax turmoil is far from over. Fallout over the ruling is already threatening to further strain global trade relations, and the U.S. economy is likely to suffer, economists told CNBC.In 6-3 decision, the high court ruled that President Trump did not have the legal authority to implement his sweeping tariffs imposed last April under the International Emergency Economic Powers Act (IEEPA).Trump later leveled new tariffs up to 15% effective immediately on an array of U.S. trading partners, further escalating global trade tensions. European Union leaders expressed dismay over the new tariffs, arguing that the U.S. policy shift would upend trade deals already reached with with the EU as well as the U.K. last year. On Monday, the EU again postponed a key vote on its deal with the U.S.The pushback against the latest U.S. tariff threat underscores deep frustration over the president's erratic trade policies, and could push foreign governments to scale back U.S. trade and lead businesses to curb expansion, investment and hiring.The result might hobble the U.S. economy. "It shifts how trade is done with the largest economy in the world, and that has economic consequences," Mike Reid, head of U.S. economics at Royal Bank of Canada told CNBC, referring to the Supreme Court ruling and new tariff push.### DownsideThe trade war drama is likely to contribute to a climate of caution among businesses and foreign governments alike, said Mark Zandi, chief economist at Moody's Analytics, leading to "nothing but downside," for the U.S. economy."Businesses don't know" what's going to happen next, Zandi told CNBC. "They're going to invest less, they're going to hire less, they're going to be less aggressive in their expansions," limiting U.S. growth.Foreign governments could react similarly amid rising uncertainty, leading them to "continue to pull away from the U.S," according to the economist."They've got to be pulling their hair out over all of this," Zandi said. "Perceptions of the U.S. are increasingly that we're a poorly managed economy, and objectively speaking, they're right. It's a bit of a mess that feels like it's getting messier."That perception could lead to efforts to divert trade away from the U.S. to a variety of other trading partners, including China.China's exports grew 6.6% in U.S. dollar terms last December compared to the same month a year earlier, topping analyst expectations and sending the nation's annual trade surplus to a record, according to Chinese customs data. Imports increased at their fastest pace in three months, the same data showed.### Trump trade taxesThe Trump administration will continue implementing its trade policy, and now plans to use a variety of sections in the Tariff Act of 1974, according to U.S. Trade Representative Jamieson Greer.President Trump is pointing to section 122 of the Tariff Act to justify his new tariffs enacted this weekend, although that section limits their effectiveness to 150 days, until mid July, after which they would have to be approved by Congress.But the administration is likely to use sections 232 and 301 of the Tariff Act to supplement its new section 122 tariffs, meaning the U.S. could continue to impose tariffs against its foreign trading partners over the next few years, at least.Others say neither investors nor economists shouldn't sound the alarm just yet.The implementation of the new trade taxes "implies little change in the effective tariff rate or our inflation forecasts in the near term," Citigroup economist Veronica Clark said in a note to clients."Eventual Section 301/232 tariffs could have an impact on certain goods prices in the future, but details are still highly uncertain," Clark wrote. "While a 10% Section 122 tariff would likely have lowered the effective tariff rate by 3-4 \[percentage points\], a 15% tariff should keep the effective tariff rate essentially unchanged (if anything, lower by ~1pp or so).While the total impact of the new tariffs remains uncertain, a few things are clear, Zandi said."The U.S. is pulling away from the world, and the rest of the world is now pulling away from the U.S.," the economist said. "Deglobalization is a weight on the economy, and ultimately, the end state is a weakened economy."_— With additional reporting provided by CNBC's Alex Harring_