Washington state's newly signed income tax on high earners is facing legal challenge, with critics arguing it violates the state constitution and could negatively impact small businesses. The measure, which includes a 9.9% tax on income of $1,000,000 or more for individuals and households, was passed on March 11 and signed by Washington Gov. Bob Ferguson on March 30. Curtis Nuccitelli, owner of Spirit Transport Systems, has joined a lawsuit by the Citizen Action Defense Fund (CADF), a watchdog group that helps Washingtonians hold state and local governments accountable. Despite these criticisms, the Washington Attorney General's Office has stood by the law, stating they expect to prevail in court.