One fantasy is held by some members of the Utah Legislature, who cling to the belief that a long-gestating plan to start collecting sales taxes on purchases Utahns make over the Internet and through old-fashioned mail order businesses is about to pay off.

It could happen. Utah and 18 other states have joined the Streamlined Sales and Use Tax Agreement and are moving toward a unified system that could begin to capture at least a portion of the taxes that now go unpaid.

But the brainstorm from Sen. Curt Bramble - that the new revenue stream from a streamlined sales tax could make up for the proposed repeal of the state's sales tax on groceries - is far too optimistic to justify any tax cuts now.

The U.S. Supreme Court says a state can't charge tax on a sale by a company that isn't physically located within its borders. Proposals for Congress to allow the collection of sales taxes on interstate transactions have been stymied for years.

Looking for a way to capture that revenue, and take away what many see as an unfair advantage distant marketers have over local merchants, the SSUTA has cooked up a voluntary plan that would ask merchants to collect and remit the tax. To encourage participation, the states are designing a simple, unified sales tax rate and offering a 1.3 percent processing fee for the merchants.

Fine. But nobody knows if it will work or how much Utah might get out of it. Estimates of $100 million a year for Utah sound good, but it wouldn't make up for the $225 million state and local governments now get from the grocery tax.

We'd be as happy as anyone to see the sales tax eliminated from groceries. It's a particularly regressive tax that hurts those least able to pay. But the loss of revenue to the state, unless balanced somewhere else, will hurt the social services that serve the poor above all.

If lawmakers are so determined to eliminate the sales tax on groceries, they should make up the revenue either with a higher tax on other goods or by broadening the base to include a sales tax on services.

If tax revenue from Internet sales really does start to pour in, then, and only then, could other taxes be reduced accordingly.