The Supreme Court announced Monday it would take up a case considering whether Congress can tax income before it is received. The case, Charles G. Moore et ux. v. United States, stems from a Washington state couple’s 2019 lawsuit against the government for a nearly $15,000 tax bill imposed on their small investment in an overseas company, from which they never earned a profit. It considers whether taxes on unrealized gains are legal under the 16th Amendment, which enables Congress to tax incomes “without apportionment among the several States.” Hank Adler, Burra Executive Professor of Accounting at Chapman University, previously...