Missouri Governor Mike Kehoe has placed Amendments 4 and 5 on the August primary ballot. Kehoe has stated that the state constitution is under threat from out-of-state special interests using ballot initiatives.

Kehoe supports Amendment 4, a measure designed to make it more difficult to amend the state constitution through citizen-led ballot initiatives. "Our constitution shouldn't be the victim of out-of-state special interests who spend millions to deceive voters and pass out-of-touch policies," Kehoe said in a video posted to the social media site X. Amendment 5, which aims to put Missouri on a path toward eliminating the state income tax, is also on the August ballot. Proponents argue that phasing out the income tax would make Missouri more economically competitive and lower the overall cost of living. Opponents say the measure would shift the tax burden onto working-class families by imposing new sales and use taxes on products and services not currently taxed. Critics also warn that higher taxes could put Missouri retailers at a disadvantage in the Kansas City and St. Louis areas due to proximity to Kansas and Illinois.

Missouri Promise PAC, which supports Amendment 5, received $1.9 million from Missouri Promise Inc. Missouri Promise Inc. is a nonprofit incorporated in Delaware in late 2023. Neither Missouri Promise Inc. nor Missouri Promise PAC discloses the identities or locations of their donors. Missouri Promise PAC has placed ads online and on TV in support of Amendment 5. Missouri Promise Inc. is led by Garrett Lott, a Missouri Republican operative and political fundraiser, and Alex Melendez, a political consultant affiliated with Clark Fork Group, an Ohio-based firm.

Marc Ellinger serves as the treasurer for Missouri Promise PAC. Ellinger said the campaign had publicly disclosed all information required under Missouri law. He said he could not address what disclosures Missouri Promise Inc. and Secure Missouri may eventually make about donors in their tax filings to the Internal Revenue Service. Secure Missouri, a Missouri nonprofit formed in 2023, contributed $1.5 million to Missouri Promise PAC. Ellinger's law office is listed as Secure Missouri's address. In 2010, Ellinger served as spokesperson for a ballot initiative that sought to require periodic votes on a 1% tax on wages paid by residents and workers in St. Louis and Kansas City. Missouri voters approved that measure, mandating that St. Louis and Kansas City submit the wage tax to voters every five years.

A campaign opposing Amendment 5 received a $1,900,001 contribution from the Missouri Realtors PAC. The Missouri Realtors PAC reports its donors in public filings with the Missouri Ethics Commission.