This statement before the U.S. Senate Committee on Commerce, Science, and Transportation is on Congress’s role in the debate over state sales taxation of online purchases. The Constitution empowered Congress with the responsibility to rein in state tax overreaching when it threatened to do harm to the national economy. Consequently, states were not permitted to tax items in interstate commerce at all, from the Founding until approximately the 1950s. There are approximately 9,600 jurisdictions in the United States that collect sales tax. Sales tax can vary by product, by time, and by location in the state. In 7 states, local governments can have a different sales tax base from the state tax base. There are five basic actions that Congress may proceed with in regards to reaffirming, modifying, or repealing the physical presence rule in order to clear up state and local taxes across the country.