Opinion | The Supreme Court Will Finally Decide What ‘Income’ Means

The Supreme Court hears oral arguments Tuesday in the most important tax case in decades. Moore v. U.S. will answer the question of whether Congress can tax unrealized capital gains as if they were income under the 16th Amendment.

The case has attracted a flood of friend-of-the-court briefs, mostly cheering for the tax collectors. Many argue outright that there is no requirement for profit to be realized—which usually means selling an asset at a profit—for a taxpayer to be hit with an income tax as the Constitution means it.