Missouri voters decisively rejected Amendment 5 on August 4, with 83 percent voting against a measure that would have phased out the state income tax and expanded sales taxes to replace the lost revenue. The overwhelming rejection marks a major setback for Governor Mike Kehoe and other Republicans who championed the constitutional amendment as a path to economic growth.
Amendment 5 would have required the state legislature to gradually reduce the individual income tax based on revenue growth until it was completely eliminated. Once the income tax was gone, lawmakers would have been prohibited from reinstating it without voter approval of a new constitutional amendment. The measure also would have given the General Assembly a five-year window to expand the state’s sales and use tax base—potentially taxing items currently exempt—to make up for the lost income tax revenue.
The current Missouri income tax is graduated, ranging from 2 percent to 4.7 percent on taxable income above roughly $9,200 annually. According to the nonpartisan Missouri Budget Project, the state’s income tax generates approximately $8.5 billion in annual revenue, representing more than half of the state’s general revenue.
Opponents of Amendment 5 argued it was fundamentally a tax swap that would harm low-income Missourians. The Missouri Budget Project found that 80 percent of people in the state would have seen a net tax increase under the measure, with the average Missourian paying over $500 more in taxes annually. That analysis highlighted a key concern: because sales taxes are regressive, placing a heavier burden on lower earners who spend a larger share of their income on taxable goods and services, shifting from income tax to sales tax would disproportionately affect working families.
Supporters of the measure countered that eliminating the income tax would spur economic growth and draw more residents to Missouri, pointing to states like Florida and Tennessee that have no income tax. Representative Bishop Davidson, a Republican from Republic who sponsored the amendment, suggested the expanded sales tax could have ranged between 4 and 6 percent. Missouri’s current state sales tax is 4.225 percent before local add-ons.
A critical weakness in Amendment 5 was the lack of specificity about what would be taxed. The amendment did not detail which items would be exempt from expanded sales taxes. Governor Kehoe had stated in January that he would never support extending sales taxes on agriculture, health care, or real estate—but those exemptions were not written into the constitutional language. Lawmakers would have made those decisions after voters approved the measure, leaving substantial uncertainty about the final tax structure.
A Cautionary Precedent from Massachusetts
Missouri’s rejection of income tax elimination is not unprecedented. Massachusetts voters have twice rejected similar measures—in 2002 and 2008—according to multiple sources tracking those ballot outcomes. In 2008, Massachusetts Question 1, which would have eliminated the state’s personal income tax, was defeated with approximately 70 percent of voters opposed. The 2002 measure also failed, though by a narrower margin.
The Massachusetts experience suggests that voters across different states and eras have been skeptical of wholesale shifts from income taxation to consumption-based taxation, particularly when the consequences for state services and tax burden distribution remain unclear.
With Amendment 5’s defeat, Missouri lawmakers remain unable to expand sales and use taxes without voter approval. The state legislature has already passed income tax cuts in recent years, reducing the top rate from higher levels, but full elimination would have required this constitutional amendment. The vote reflects public resistance to a fundamental restructuring of Missouri’s tax system, even as the state’s current tax code—last substantially modified in 1931—continues to face criticism from some lawmakers as outdated.
Sources
- St. Louis Public Radio — rejection of Amendment 5 with 83% voting no, Governor Kehoe’s prioritization of the measure, revenue impact analysis from Missouri Budget Project, and details of the amendment’s structure and exemptions
- Ballotpedia — Amendment 5 details and requirements for phasing out income tax
- Multiple news outlets (KRCG-TV, NewsFromTheStates, Kansas City Star) — confirmation of Amendment 5 rejection and Massachusetts precedent of 2002 and 2008 income tax elimination ballot measures
- Tax Foundation — current Missouri income tax rates ranging 2% to 4.7%
- Missouri Independent — first-year cost of income tax elimination proposal at $4.2 billion and historical context on income tax reform efforts
