President Donald Trump's use of sweeping tariffs faced sharp questioning at the Supreme Court on Wednesday, in a case with major implications for the president's agenda and the global economy. A majority of justices, including several conservatives, expressed doubts about the White House's justification of the import duties, which the president has said are necessary to restore America's manufacturing base and fix its trade imbalance. The measures are being challenged by a number of small businesses and a group of states, which contend that the president has overstepped his authority in imposing the levies, which are in effect a tax....