IEEPA allows a president to unilaterally implement a new tariff program to oversee U.S. imports, without Congress having the ability to provide any oversight or regulation on how those tariffs are imposed. He previously threatened to use IEEPA in 2019 to impose a five percent tariff on Mexican-made goods – with a ceiling of 25 percent — unless Mexico's government took action to slow the number of undocumented immigrants entering the U.S. However, after the U.S. and Mexico negotiated the "remain in Mexico" policy, Trump withdrew the tariff threat.

While Trump was largely able to impose tariffs during his first administration without Congress, one expert is skeptical that Trump will be able to force through his proposed new tariffs under IEEPA. Alan Wm. Wolff, who is a former deputy director-general of the World Trade Organization, wrote in a November blog post that the president-elect likely wouldn't be able to justify a national security emergency to singlehandedly raise tariffs without congressional input.

"Can it be used against trade with all countries, our allies and friends in Europe and Asia, in the Americas, not to mention the poorest countries in Africa? That would simply be too large a power grab to have been within what Congress intended in this statute," he argued.

As Wolff wrote, Trump may have difficulty convincing Congress that there's a national security situation dire enough to warrant an economic emergency declaration. The U.S. economy has been healthy by all measurable metrics for the last half of President Joe Biden's administration, despite him taking office under abnormally high inflation and interest rates due to the stress caused by the Covid-19 pandemic. Additionally, real wages have been steadily climbing since 2022, and unemployment rates have remained historically low despite economist's predictions that the jobless rate would have to go up significantly to lower inflation.

“Over the next four years the United States is going to take off like a rocket ship. But really it’s already doing it," Trump said in a Tuesday press conference.