Now that the online shopping behemoth has been adopting a locally-based business model, it has reversed positions to join Walmart and other brick-and-mortar chains in pushing for Internet-wide sales tax collection:
[T]he writing is on the wall for Amazon. Plainly, its helping itself by making sure its competitors have to pay tax too. A representative of Amazon.com urged Congress to enact the Marketplace Fairness Act. The bill, S. 1832, would require online retailers who exceed a revenue threshold to collect and remit state sales tax on online purchases in all states. The Senate’s Commerce, Science, and Transportation Committee hearing doesn’t mean passage is a certainty. Still, consider that the Senate bill has 240 supporters including Best Buy, Target and Walmart, not to mention Amazon. But eBay objects to the small-business exemption which maxes out at $500,000 in gross annual sales.
Another bill, H.R. 3179, would also "replace the physical-presence rule with a requirement that state and local governments simplify their tax policies if they want to collect sales taxes from out-of-state retailers". There's an interesting debate over whether this constitutes a new tax or not: