President Donald Trump still has options to keep taxing imports aggressively even after the Supreme Court struck down the tariffs he imposed last year on nearly every country on earth.The Justices didn’t buy the president’s sweeping claims of authority to impose tariffs as he sees fit. But Trump can re-use tariff powers he deployed in his first term and can reach for others, including one that dates back to the Great Depression.”It’s hard to see any pathway here where tariffs end,” said Georgetown trade law professor Kathleen Claussen. “I am pretty convinced he could rebuild the tariff landscape he has now using other authorities.”Trump had claimed nearly boundless authority to impose tariffs under 1977 International Emergency Economic Powers Act (IEEPA). But opponents argued before the Supreme Court that that power wasn’t necessary because Congress delegated tariff power to the White House in several other statutes – though it carefully limited the ways the president could use the authority.Tariffs have been a cornerstone of Trump’s foreign and economic policy in his second term, with double-digit “reciprocal” tariffs imposed on most countries, which he has justified by declaring America’s longstanding trade deficits a national emergency.The average US tariff has gone from 2.5 per cent when Trump returned to the White House in January to nearly 17 per cent a year later, the highest since 1934, according to calculations by Yale University’s Budget Lab.The president acted alone even though the US Constitution specifically gives the power to tax and impose tariffs to Congress.Countering unfair trade practicesThe United States has long had a handy cudgel to wallop countries it accuses of engaging in “unjustifiable”, “unreasonable” or “discriminatory” trade practices. That is Section 301 of the Trade Act of 1974.And Trump has made aggressive use of it himself – especially against China. In his first term, he cited Section 301 to impose sweeping tariffs on Chinese imports in a dispute over the sharp-elbowed tactics that Beijing was using to challenge America’s technological dominance. The US is also using 301 powers to counter what it calls unfair Chinese practices in the shipbuilding industry.There are no limits on the size of Section 301 tariffs. They expire after four years but can be extended.But the administration’s trade representative must conduct an investigation and typically hold a public hearing before imposing 301 tariffs.Experts have said Section 301 is useful in taking on China. But it has drawbacks when it comes to dealing with the smaller countries that Trump has hammered with reciprocal tariffs.Targeting trade deficitsIn striking down Trump’s reciprocal tariffs in May, the US Court of International Trade ruled that the president couldn’t use emergency powers to combat trade deficits.That is partly because Congress had specifically given the White House limited authority to address the problem in another statute: Section 122, also of the Trade Act of 1974. That allows the president to impose tariffs of up to 15 per cent for up to 150 days in response to unbalanced trade. The administration doesn’t even have to conduct an investigation beforehand.But Section 122 authority has never been used to apply tariffs, and there is some uncertainty about how it would work.Protecting national securityIn both of his terms, Trump has made aggressive use of his power – under Section 232 of Trade Expansion Act of 1962 – to impose tariffs on imports that he deems a threat to national security.In 2018, he slapped tariffs on foreign steel and aluminum, levies he’s expanded since returning to the White House. He also plastered Section 232 tariffs on autos, auto parts, copper, lumber.In September, the president even levied Section 232 tariffs on kitchen cabinets, bathroom vanities and upholstered furniture.Reviving Depression-era tariffsNearly a century ago, with the US and world economies in collapse, Congress passed the Tariff Act of 1930, imposing hefty taxes on imports. Known as the Smoot-Hawley tariffs (for their congressional sponsors), these levies have been widely condemned by economists and historians for limiting world commerce and making the Great Depression worse. They also got a memorable pop culture shoutout in the 1986 movie ‘Ferris Bueller’s Day Off’.Section 338 of the law authorises the president to impose tariffs of up to 50 per cent on imports from countries that have discriminated against US businesses. No investigation is required, and there’s no limit on how long the tariffs can stay in place.Those tariffs have never been imposed – US trade negotiators traditionally have favoured Section 301 sanctions instead – though the United States used the threat of them as a bargaining chip in trade talks in the 1930s.In September, Treasury Secretary Scott Bessent said the administration was considering Section 338 as a Plan B if the Supreme Court ruled against Trump’s use of emergency powers tariffs.