U.S. President Donald Trump on Wednesday issued a blitz of tariff announcements ranging from changes to previously threatened levies on imports of copper and on goods from Brazil to ending an exemption from tariffs for small-value shipments from overseas.

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.

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.

The move marks a sharp escalation in Trump’s longstanding effort to reshape global trade, signaling a shift toward universal tariffs for nations that do not individually negotiate terms with the U.S.