It seems your newly elected Congress is pressing forward with plans to implement SSTP (State Simplification Tax Project). This bill, if passed, will require all US buyers to pay sales tax AND all sellers to collect and remit sales taxes to each taxing authority of the purchaser. At present, that's over 7,600 taxing jurisdictions. If the bill is passed, the SSTP allows for a different rate for each zip code - that's as many as 49,000 different jurisdictions. More when you consider that there are zip codes with split jurisdictions. (Up to 4 for my zip alone.)
Right now, I remit sales taxes collected for items purchased within Texas at my location's rate. Because I'm outside any city limits, the tax rate I charge is about 1.5% less. If this bill goes through, online sellers would have to charge and remit sales taxes for/to each buyer's jurisdiction. While this isn't that bad for the volume I do online, it certainly will be a complicated mess for sellers that sell thousands of items a month.
What were they thinking? This could put Ebay and every online catalog out of business.