We analyze the choice politicians face when seeking votes from groups that lobby for sales tax rate decreases or from groups that lobby for certain tax exemptions, given the constraint that each politician wants to raise a certain amount of revenue. Using the application of sales taxes and sales tax exemptions we develop a model predicting a positive relationship between the number of sales tax exemptions and the sales tax rate. We find support for this hypothesis. A one-unit increase in the number of exemptions is associated with an increase between 0.10 and 0.25 percent in the sales tax rate. Our results provide one explanation of why estimates of revenue increases generated by a sales tax increase are often too optimistic.