The Supreme Court’s ruling represents a half-victory for Mexico, the United States’ main trading partner. The Republican’s reaction to the judicial setback was immediate and set a global tariff of 10%, under section 122, which will come into force next Tuesday. However, products from Mexico and Canada under the USMCA have been exempt from this tariff, according to the executive order, published this Friday. Although Mexico still must pay sectoral tariffs on steel, aluminum, automobiles, auto parts, copper and other products, this concession will safeguard part of the intense binational trade exchange estimated at more than 800,000 million dollars.
The tariff tsunami in the United States has as its starting point this Friday’s decision by the US Supreme Court to declare a good part of Trump’s tariffs unconstitutional, an unprecedented ruling to which the Republican has reacted quickly with the imposition of a global tariff of 10%. However, the exception given to Mexico and Canada, under the protection of the USMCA, is in line with the same concession that Mexico received last April on reciprocal tariffs. According to official figures, more than 80% of Mexican exports comply with the trade agreement, so they enter the US market tariff-free.
The new global tariff, which Mexico and Canada have avoided, is based on section 122 of the Trade Act of 1974. This mechanism gives the president the authority to impose temporary import restrictions – such as tariffs or quotas – on goods from other countries under specific conditions for a maximum of 150 days. Unlike other provisions that require lengthy investigations or international coordination, Section 122 is designed to be an immediate tool to address urgent trade imbalances or retaliatory measures. To this new rate must be added the tariffs that Mexico currently pays under section 232, for reasons of national security on steel, copper, aluminum, semiconductors, wood and automobiles without US content, among other goods.
Gabriela Siller, Director of Analysis at Banco Base, explains that the economic impact on Mexico of removing the 25% tariffs supported by the IEEPA will be low, since more than 80% of the goods were already exempt from that tariff for complying with the USMCA. The specialist indicates that, thanks to the USMCA, the effective tariff that Mexico pays to the United States was around 4.3%, while nations like China have a rate of more than 29%. After the Supreme Court’s ruling, nations with reciprocal tariffs will reduce their tariffs and Mexico will thus lose its relative advantage in trade matters over other countries. “Mexico may end up being affected. Tariffs under the IEEPA were not being charged to the letter and Trump could choose to impose more sectoral tariffs,” he says.
Ignacio Martínez Cortés, coordinator of the Laboratory of Analysis in Commerce, Economics and Business at UNAM, says that Trump can use other legal provisions to impose tariffs, such as the Trade Law of 1974, the Trade Expansion Law of 1962, the Tariff Law of 1930 and also the Trade Law of 1974, among others. “The United States, in the hands of Donald Trump, is not being handcuffed by the Supreme Court of Justice, but also has other mechanisms to continue imposing tariffs. What is certain is that the ruling of the Supreme Court, without a doubt, on the eve of the midterm elections, next November, represents a tremendous blow for Trump,” he concludes.
Sources from the industrial sector agree that this unprecedented ruling by the Supreme Court could bring more pressure to the company. “It seems to me that it does not help Mexico, it reduces the incentive of the chains to come to our country by removing the tariff from other countries. On the other hand, I imagine that the Trump team is lining up other mechanisms to reestablish tariffs where they could end up including us. Unfortunately, the tariffs of section 232 do not touch them,” says a businessman in the steel sector.
Since arriving at the White House, Trump has imposed indiscriminate tariffs on more than a hundred countries. Rates range from 15%, which it has set for most blocks, to 50% for India or Brazil. Despite being partners in the , the Republican has imposed special taxes against Mexico on specific products such as steel and aluminum, automobiles, copper and semiconductors. Despite this tariff wall, at the end of 2025, the Latin American country managed to position itself as the main trading partner of the United States with exports of more than 534.8 billion dollars, surpassing Canada and China.
The Supreme Court’s ruling is a blow to Trump’s trade plans and a financial setback for the United States due to the tax refund that it will have to make to the countries from which it charged reciprocal tariffs. However, this setback, far from intimidating the Republican, has given him more fuel to radicalize his protectionist position and use other national security mechanisms to apply more tariffs.
