Mike Kehoe’s plan to replace Missouri’s individual income tax with an expanded sales tax, the keyword was trust. The push to replace Missouri’s individual income tax is an effort to modernize the state’s tax structure, Patterson said. The individual income tax was first enacted in 1917, and a sales tax began in 1937. The income tax is a drag on the state’s economy compared to states that have no personal income tax, he said. After deductions, a married couple with a total income of about $36,000 pays no state income tax.