To win in court, the Trump administration will have to argue against a pair of legal theories that conservatives have spent years developing as a way to check executive power.

Companies, consumers and foreign countries have been paying close attention to President Donald Trump’s aggressive policy of placing tariffs on foreign goods. Soon, the courts will weigh in on whether Trump has the power to levy those tariffs in the first place — a high-stakes legal battle that will either affirm a key pillar of Trump’s economic policy or cut it off at the knees.

President Donald Trump signed an executive order Wednesday to impose his threatened 50% tariffs on Brazil, setting a legal rationale that Brazil’s policies and criminal prosecution of former President Jair Bolsonaro constitute an economic emergency under a 1977 law.

Brazil President Luiz Inacio Lula da Silva’s defiant response to Donald Trump’s 50% tariff threat was validated Wednesday — at least in the short term — with markets and businesses breathing a collective sigh of relief at the long list of exemptions to the levies.

The US is seeing increased tariffs income, but there are signs of some countries diverting trade from America.