What's next for Trump's tariffs after Supreme Court ruling

Based on the visibly simmering anger that U.S. President Donald Trump barely managed to suppress throughout his news conference on the Supreme Court's tariff decision, it's a fair bet that Friday was the worst day so far of his second term.

Three conservative justices — including two of Trump's own nominees — tipped the balance on the court to hand the president a 6-3 defeat in what he had previously called the most important case in U.S. history.

The ruling means Trump does not have the power to impose tariffs through the International Emergency Economic Powers Act (IEEPA), which he had attempted to use as the foundation of his tariff-fuelled trade war on the rest of the world.

With that foundation now shattered, Trump is trying to shrug it off and lay another one.

"Their decision is incorrect. But it doesn't matter because we have very powerful alternatives," he told the news conference.

Trump announced he'll use other legally established ways of imposing tariffs, starting with a 10 per cent levy worldwide through a different piece of legislation, and claimed his Plan B could bring even more tariff revenue into the treasury than Plan A did.

"The numbers could be far greater than the hundreds of billions we've already taken in," he said, without providing evidence.

That prompts the question: If these alternative ways of imposing tariffs are bigger and better than the one struck down by the Supreme Court, why didn't Trump go with Plan B first?

The fine print of Trump's new 10 per cent temporary import duty gives some hints of why it was the backup rather than Plan A. The tariff lasts for 150 days, at which point it falls to Congress to extend it.

Despite calling it a global tariff, Trump has given exemptions to a litany of items, including passenger vehicles, energy products, pharmaceuticals, fertilizers, beef, tomatoes, oranges and some electronics.

Also exempt: Canadian goods that comply with the Canada-U.S.-Mexico Agreement, which covers the vast majority of Canadian exports south of the border.

Trump's reaction to the ruling could be seen as the latest example of a pattern of being unwilling to admit that he has lost, the 2020 presidential election being the biggest.

Consider the combative, defiant and unrepentant language he used in Friday's news conference, revealing just how badly he wanted to stick with Plan A.

He slammed the Supreme Court justices who ruled against him as "fools and lapdogs" and "unpatriotic and disloyal." He claimed the court has been "swayed by foreign interests."