The Supreme Court expressed skepticism on Tuesday towards a conservative-backed challenge seeking to prevent Congress from ever implementing a tax on wealth. Conservative and liberal justices scrutinized a lawyer representing a Washington state couple who aimed to dismiss a "repatriation" tax on large corporations' overseas earnings, an important provision of the 2017 Republican tax bill.

While the case revolves around a specific tax, some wealthy individuals and pro-business groups hope for a broader ruling that would eliminate the possibility of a wealth tax, a proposal gaining traction on the left but raising constitutional questions.

During the lengthy argument session, Justice Elena Kagan challenged the lawyer's attempt to establish distinctions between the repatriation tax and other long-standing taxes. Kagan pointed out that there is a historical precedent for such taxes.

However, certain justices appointed by the GOP, namely Neil Gorsuch and Samuel Alito, expressed caution about delivering a complete victory for the government. They sought an outcome that would preserve the court's ability to restrict federal taxing powers in future cases.

Gorsuch raised concerns about the limitless nature of the government's argument, stating that it opens the door for federal authorities to tax almost anything they deem as income. He emphasized his reluctance to leave such a broad interpretation open.

Solicitor General Elizabeth Prelogar countered Gorsuch's statement by citing previous Supreme Court decisions that grant the federal government extensive authority to tax various investment types. By the conclusion of the session, the justices appeared inclined towards a narrow ruling favoring the government.

Earlier in the year, Justice Alito attracted attention when he publicly rejected calls for his recusal from the tax case due to his connection with one of the lawyers representing the Washington couple. Alito sought to assure fairness in handling the arguments presented by both sides.

The case of Charles and Kathleen Moore, the couple challenging the repatriation tax, stems from their complaint about receiving a $15,000 tax bill on an investment in an Indian power tool company that generated no income for them. They argue that the tax is on their property rather than income, which they claim violates the Constitution's prohibition on federal property taxes.

If the Supreme Court were to invalidate the repatriation tax, it could result in big companies receiving substantial tax refunds. Additionally, a broad ruling could thwart the enactment of wealth tax proposals put forth by Senator Elizabeth Warren and other progressive lawmakers. The Moores sought the court's intervention specifically to prevent the possibility of a wealth tax.

Tax experts express concern that if the justices, who lack expertise in tax law, do not exercise caution, they may inadvertently create significant loopholes in the tax code. Certain provisions in the code tax individuals before they actually receive income, aiming to prevent tax evasion. A sweeping ruling against taxes on "unrealized gains" could cast doubt on several sections of the code.

The government highlighted these concerns, underscoring the long history of taxes in the United States and their connection to income. Solicitor General Prelogar warned that a ruling in favor of the Moores could have far-reaching implications and result in trillions of dollars in lost tax revenue.

Justice Alito raised an intriguing question about the possibility of a tax on income functioning as a tax on wealth, using the example of a self-made billionaire who started a small business decades earlier. The complexity of taxing accumulated income over time was acknowledged by Prelogar, who noted the absence of a comparable tradition to support that type of income taxation.

Among the court's Republican-appointed justices, Justice Brett Kavanaugh appeared less concerned about the government's position. He dismissed the notion of a broad-based wealth tax, finding it detached from political reality and provoking laughter in the courtroom.

The Supreme Court's decision in this case, which involves nuanced arguments about taxing wealth and income, will have significant ramifications for future tax policy and the role of the federal government in taxation.