A Washington state couple's nearly $15,000 tax bill was debated by the Supreme Court on Tuesday, in a case the Biden administration says could have "far-reaching consequences," potentially costing the government more than $5 trillion. At issue is whether ...

The Moores were taxed $14,729 on that investment under a provision in the GOP’s signature 2017 tax law called the “mandatory repatriation tax” (MRT), which imposed a one-time tax on U.S. individuals and companies who have a significant stake in foreign corporations controlled by Americans.

In a Supreme Court case revolving around one couple’s disputed tax bill, justices Tuesday wanted to explore the case’s potential broader implications, while opposing lawyers wanted them just to stick to the case at hand.

Their eventual decision in the case could severely limit congressional options in enacting tax policy, and it could cost the federal government trillions of dollars in corporate taxes.

The case before the justices Tuesday could have sweeping implications for the U.S. tax system and derail proposals from some Democrats to create a wealth tax.

The challenge by a Washington state couple is widely viewed as an effort to preemptively block Congress from creating a wealth tax.

The court looked unlikely to impose strict new limits on Congress’s power to tax income, with some conservative and liberal justices alike signaling wariness about upending long-settled principles of the federal tax code.