Editor's Note: This two-part series explores the implications for global trade of a potential second Trump term. Part 1 focuses on Trump's trade priorities, while part 2 will focus on what countries Trump could target, and how.

Should former President Donald Trump return to the White House in 2025, a second term would see higher tariffs on imports, new trade wars, greater U.S. inflation and accelerated global supply chain diversification. Throughout his 2024 presidential campaign, Trump has proposed a variety of protectionist trade measures, including in June, when he reportedly proposed to Republican lawmakers in a meeting on Capitol Hill raising tariffs as a way to offset cuts to — and ultimately to replace — the U.S. income tax. The proposal is unrealistic, as it would require unlikely congressional approval and a dramatic hike in U.S. tariffs given that in 2023 income generated from customs duties accounted for less than 2% of total federal government revenue. But the proposal alone illustrates Trump's focus on raising tariffs as a key part of his economic platform. Other proposals that Trump, or his close allies, have floated over the last year include raising tariffs on all imports by 10%, raising tariffs on imports from China by 60% and implementing a policy of "reciprocal" tariffs that would see the United States apply the same tariffs on other countries for individual goods that they apply on U.S. goods. 

• Trump has vocally supported the U.S. automotive industry, having threatened to put tariffs on Chinese vehicles produced in Mexico, suggesting the threat of national security-related tariffs on vehicles will eventually resurface if he returns to the White House. While Trump has not been as vocal about resurrecting national security-related tariffs on European and other foreign automakers like those he threatened during his first term, his support for the auto industry and the upcoming 2026 USMCA review provides further evidence that national security-related tariffs on the automotive industry could resurface.
• Trump's view on economic and trade policy is extremely mercantilist, viewing a trade deficit as inherently bad for the U.S. economy and believing that bilateral trade deficits with other countries demonstrate that one side is winning at the other's expense. The U.S. trade in goods and services deficit reached a record $951 billion in 2023. The U.S. trade in goods deficit has exceeded $1 trillion in each of the last three years. 

In a second term, Trump is likely to have more freedom within his administration — and from Congress — to push for more aggressive trade measures. During Trump's first presidency, a significant split emerged among top officials between those who were pro-free trade and conventional trade policy among high ranking officials (such as then-National Economic Council heads Gary Cohn and Larry Kudlow and -Treasury Secretary Stephen Mnuchin) and those who were protectionist supporters (such as then-U.S. Trade Representative Robert Lighthizer, -Commerce Secretary Wilbur Ross and -White House National Trade Council head Peter Navarro). Trump has promised that his Cabinet in a second term would be more in line with his own protectionist views, meaning internal discussions about new tariffs are more likely to become official policy. Moreover, there is no indication that Trump will appoint pro-trade Wall Street stalwarts like Cohn and Mnuchin to similar positions in a second term and, instead, Lighthizer is reportedly eyeing the treasury secretary position and has spent much of the three years since he left the office of the U.S. Trade Representative proposing more protectionist policies. Trump may also face more limited blowback on Capitol Hill. During his first term, Trump's trade policies faced frequent opposition from pro-free trade Republicans in Congress, particularly in the Senate, but this would be less likely in a second term. Today's Republican Party is much closer to Trump's views than it was a decade ago. If Trump wins the White House, the Republicans are also likely to have swept control of Congress. Furthermore, the U.S. court system in his first term provided little to no resistance to the expansive interpretation by Trump and his advisers regarding the authority delegated by Congress to the president on trade matters, suggesting that the courts will also provide little resistance in a second term. 

Trump's threats to impose 10% tariffs on all imports, implement a reciprocal tariff plan and more generally raise tariffs to reduce the income tax are the least likely to come to fruition due to the risks of severe economic blowback and legal restraints. Even if his advisers are more supportive of tariffs in a hypothetical second Trump administration, significant popular opposition to an across-the-board tariff on all U.S. imports or imports from countries with which the United States does not have a free trade agreement is likely because such a tariff would lead to major price increases. The conservative think tank the American Action Forum has estimated the tariffs, along with likely retaliation by U.S. trading partners, would reduce U.S. gross domestic product by $62 billion. The liberal think tank the Center for American Progress Action Fund has estimated that the impact of the 10% tariff proposal plan would cost a typical U.S. household $1,500 annually. While proponents of Trump's tariffs argue that they would have only a limited impact on inflation, the heavy use of new tariffs would be effectively a regressive tax, affecting those with lower incomes the most and driving up the cost of living for them regardless of whether the broader impact on inflation was limited. Trump's more radical proposal to significantly increase tariffs and reduce the income tax is even less realistic. Not only would it be a highly regressive shift in U.S. tax policy since many poorer Americans pay lower income taxes and spend more on consumption than wealthier Americans who save more and pay higher taxes, it would require a 100- or 1,000-fold increase in U.S. tariffs to even become comparable to the amount of revenue that income taxes generate in sheer dollar amounts. It would also likely cause an immediate decline in U.S. imports and a major recession. 

• Trump's legal authority to implement 10% tariffs on most imports, reciprocal tariffs or increase tariffs in a way to offset income tax reductions is much more limited than any of the product-specific or country-specific tariff authorities that Trump has proposed using or did use in his first term. Congressional action would likely be needed for these measures to be permanent or survive litigation. Trump could use Section 122 of The Trade Act of 1974 to address a large balance of payments deficit to apply tariffs up to 15% on certain goods, but these tariffs can only be temporary, lasting just 150 days unless extended by Congress. Trump could also use the International Emergency Economic Powers Act of 1977, which U.S. presidents primarily use to implement sanctions, but the statute does not specifically grant the president the power to implement tariffs. Trump threatened to use IEEPA in 2019 to place 5% tariffs on just Mexico to compel Mexico City to change its southern border policies.
• Trump is still likely to back some country-agnostic tariffs targeting specific sectors, such as further expanding steel and aluminum tariffs, but most tools that would allow Trump to target all countries at once with a single trade measure require that measure to be focused on just a handful of related goods (like all steel goods and/or steel products) rather than on all imports.
• Any move by Trump to use executive authority to place 10% tariffs on imports would not be the first time a U.S. president has done so. In 1971, then-President Richard Nixon placed a 10% surcharge on all dutiable imports among a host of other economic policies to address high inflation in what became known as the "Nixon shock." Courts never weighed in on the legality of Nixon's moves, which he predicated on the Tariff Act of 1930 and the Trading With the Enemy Act of 1917 as his legal bases. The tariffs were ultimately removed three months after the shock.

Next: What countries would Trump tariff in a second term, and how might they respond?