Amazon.com (NASDAQ:AMZN) may be hopping aboard the national online sales tax train. According to yesterday's Washington Post, proponents of bicameral, bipartisan legislation have been trying to woo Amazon into lending its support to their bills.

Once considered too politically risky and controversial to touch, the issue of online sales tax collections has heated up this year amid record budget deficits for states. Back in February, a group of online retailers with offline presences, including Wal-Mart (NYSE:WMT), Target (NYSE:TGT), and Toys "R" Us (NYSE:TOY), announced that they'd reached an agreement with 38 states and the District of Columbia to collect sales taxes on purchases made by their residents. Now bills are being introduced in Congress to take that effort further, while at the same time simplifying the complex tax code for easier compliance.

It's not entirely surprising to hear that Amazon may be willing to give its support to the online sales tax movement. Its chief financial officer said at an investment conference in May that he believes online sales tax collections are "inevitable." However, should Amazon come out solidly in favor of online sales taxes, it would be a blow to other Internet-only retailers that have been relying on their lack of a local sales tax "nexus" to defend their no-tax status.

Amazon reportedly wants the annual sales threshold for tax collection brought down from $5 million to $25,000, meaning essentially that if they're going to get taxed, they want nearly everyone to get taxed. The House sponsors didn't agree and went ahead with their version of the bill, while the Senate side considered Amazon's proposal.

There was no official word out from Amazon today about its tax opinions and support (or lack of it) for the new legislation. Still, it's an interesting story, and one to keep watching.