It was bound to happen. A Missouri state senator plans to seek legislation in 2019 that would cap the amount of sales taxes that local governments can levy.The St. Louis area senator, Andrew Koenig, has filed a bill to cap the combined local sales taxes for any Missouri city at a little more than 7.2 percent.The state senator believes there are too many taxing jurisdictions in Missouri in which both cities and smaller jurisdictions, such as community improvement districts, can impose sales taxes.The bill would exempt from the cap taxes collected mostly from visitors, such as hotel and rental car taxes.A cap on sales taxes at 14 percent didn’t go anywhere in the last session of the General Assembly.We have watched with keen interest what can be accomplished on the local levels of government with sales taxes. Sales taxes saved Franklin County from bankruptcy. We are sure that has been true in other counties in the state.As long as sales taxes are approved by voters, we can’t be convinced that any cap is needed. Many sales tax measures have sunset provisions.Cities and citizens have benefited greatly from revenue from sales taxes. One initiative that comes to the forefront are the sales taxes that enabled Warrenton to fund construction of a new Interstate 70 interchange. The two half-cent taxes have a sunset provision. The west interchange provides improved access to that area of the city, which officials hope will spur new economic growth.A state sales tax study committee should be created to study the issue and make recommendations. Lawmakers on the state, county and city levels should be members. The latest bill should be trashed.