It is not about imposing a new tax on the Internet, but about shifting the requirement for collecting an existing tax from the state to the merchant.

Internet retailers know this, but in the battle for hearts and minds the talking point of "taxing the Internet" sings more loudly.

They are on solid ground when they complain that the current mosaic of more than 7,500 state and local taxes codes is bewildering in its complexity. The burden of figuring out which days of the week certain items are subject to taxation in certain jurisdictions would be an enormously expensive task, they say.

I've heard both sides of the argument. Brick-and-mortar retailers like to point out that e-commerce exists in the age of computers, after all, and that there is software to take care of these things. It is worth noting that Amazon, the company that protested most loudly against New York's efforts to impose tax-collection requirements on online retailers last year, powers the e-commerce platform for Target.com, and therefore (presumably) has already figured out how to calculate sales taxes for all the localities in each of the 50 states where Target has physical stores.

New York managed to write its e-commerce tax-collection requirement into its budget last year, and Amazon and Overstock have challenged it in court.

But the federal law would be different. Instead of the novel loophole New York hit upon (which essentially equated in-state Web-site owners who link to e-commerce sites like Amazon as sales representatives, enough to trigger the "physical presence" tax-collection requirement established in a 1992 Supreme Court case), Congress could require all online merchants to collect and remit sales taxes, irrespective of their affiliate programs.

The legislation understood to be forthcoming would also seek to simplify the tax codes across the country, picking up the nearly decade-old mission of a coalition of states called the Streamlined Sales Tax Project, which estimates that annual revenue losses from uncollected e-commerce sales taxes will total between $11.4 billion and $12.65 billion by 2012.

Politically, this is a loser. I'm inclined to agree with Stifel Nicolaus analyst Blair Levin, who today noted that efforts to impose "anything that smacks of a tax increase" will be an "uphill fight."

"It's generally harder to pass controversial legislation than it is to block it, and in this case we note continuing resistance, particularly among Republicans but also among Democrats, to taking actions that can be seen as raising taxes, particularly during a recession," Levin said

So rest assured that the legislation will be headed for a lively debate flush with saber-rattling rhetoric. But remember, it's not a new tax, just a new tax for the people who didn't pay it in the past, either because they didn't know they had to or just chose not to.