Always preparing for plan B: WH as Trump's tariff power faces SC test

"The White House is always preparing for plan B. It would be imprudent of the President's advisors not to prepare for such a situation," Leavitt said. "We are 100% in the President and his team's legal arguments and the merits of the law in this case. We remain optimistic that the Supreme Court is going to do the right thing."

Leavitt further stated that the issue extends beyond Trump's presidency. "This case is not just about President Trump, it's about the use of the emergency authorisation of tariffs for future Presidents in the administrations to come," she said, adding that Trump views economic security as inseparable from national security.

Ahead of the hearing, Trump described the case as critical to the nation's future."Tomorrow's United States Supreme Court case is, literally, LIFE OR DEATH for our Country," he wrote on Truth Social.

"With a Victory, we have tremendous, but fair, Financial and National Security. Without it, we are virtually defenceless against other countries that have, for years, taken advantage of us. Our Stock Market is consistently hitting record highs, and our country has never been more respected than it is right now. A big part of this is the Economic Security created by Tariffs, and the Deals that we have negotiated because of them."

Meanwhile, Treasury Secretary Scott Bessent confirmed he will attend the hearing in person. "I'm actually going and sit hopefully in the front row and listen, have a ringside seat," he said on Fox News.