Democrats in Congress and the Washington state government are pushing the Supreme Court to strike down President Trump’s International Emergency Economic Powers Act tariffs on separation-of-powers grounds, claiming that allowing the duties to stand would allow the president to seize “core” legislative powers in defiance of the constitution. “Only Congress, not the President, has the power to ‘lay and collect Taxes, Duties, Imposts and Excises,’ and Congress cannot delegate those powers to the President. The President’s exercise of power here...