Last Thursday Senate Finance Committee Chair Ron Wyden (D-OR) introduced legislation to tax the unrealized capital gains of those with assets over $1 billion and those with incomes of $100 million or more for three consecutive years. The legislation, dubbed the “Billionaires Income Tax,” is cosponsored by 15 Senate Democrats and would impose a tax on the appreciation of assets, regardless of whether those assets are sold.

Wyden’s bill is the latest iteration of proposals to tax the wealthy. Opponents have argued the proposal violates the constitution and comes a week before the Supreme Court hears arguments in Moore v. U.S., a case that may rule on the constitutionality of wealth taxes. The Supreme Court’s decision and opinion in Moore will be released next year. Wyden’s legislation has little chance of passing the House of Representatives, where Republicans who oppose wealth taxes are in the majority. But the legislation will highlight the issue of income inequality that Democrats plan to focus on in their 2024 election campaigns, and which will be a major issue in the presidential campaign.