<h1>Presidential tariffs prompt legal uncertainty after court rejection of broader authority, spurring market volatility and potential litigation.</h1> The article reports that the president announced a temporary import tariff measure after the Supreme Court struck down a broader reciprocal tariff regime, raising questions about the scope of presidential tariff authority and the likelihood of subsequent litigation. The announcement produced market volatility as investors weighed legal uncertainty over trade policy and possible challenges to the new, narrower tariff action.