That's different and understandable. Everyone wants to have to comply with one set of regulations instead of one set of regulations plus fifty more additional sets of regulations (or more with counties/cities) that require additional effort to comply with and ensure the correct ones are complied with. Just the additional labor costs for lawyers must be real. Add to that the need to have special cash registers for one state, or other changes, and it gets pretty expensive. Hell, Home Depot would probably rather one national sales tax (regardless of whether it's higher or lower than the current national average) over the complexity of the current sales tax code. Just for the operational simplicity.