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.

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 justices looked for an even keeled ruling in a case that has the potential to leave the government out trillions in tax revenue.

The high court weighs challenge to Congress' broad power to tax corporate wealth in a case that could shield wealthy Americans with overseas investments.

The Supreme Court seems inclined to uphold a tax on foreign income while leaving questions about a never-enacted tax based on wealth instead of income for another day.

A decision in favor of Charles and Kathleen Moore of Redmond, Washington, could strike down a provision of the 2017 tax bill that is expected to bring in $340 billion and threatens other provisions of the tax code.