Call it a gravy train, or just a regular old milk truck, but Senator Clinton is on board. Last month, New York’s junior senator introduced yet another attempt to expand the reach of milk tariffs yet further. Not satisfied that Manhattanites are already paying as much as $4 a gallon of 2% or skim, she also wants to increase the price of “cheese foods” like Velveeta.

She doesn’t phrase it quite that way; she’d prefer to say she’s “closing a loophole” in the current web of tariffs and quotas that protects dairy farmers at the expense of consumers. But the effect is the same.

The loophole in question currently allows tariff-free import of milk protein concentrates, a form of powdered milk product used especially in so-called cheese foods, as well as in a bewildering array of processed snacks. Although American dairy farmers have only recently started producing such concentrates themselves, the imports compete with another powder called nonfat dry milk, which has traditionally been an important American product; the two are virtually interchangeable as ingredients, according to Roger Eldridge of the National Milk Producers Federation. But while foreign nonfat dry milk is subject to a tariff, the concentrated protein version is not. So milk farmers abroad need only to increase the protein content in the powder a little to get in under the radar.

This, according to Mrs. Clinton’s press release, cost New York dairy farmers $100 million in revenue in 2004 alone, since the more expensive domestic powder can’t compete with the cheaper foreign good unless a tariff artificially increases the foreign price. Which is why, Mrs. Clinton contends, dairy producers are crying in their milk over competition from “unfair and unregulated imports.” Never mind that government has caused this problem in the first place: By one count, price supports boost the cost of the domestic powder by 23%.

The good news is that a previous attempt to place a tariff on the concentrated powder failed, despite the best efforts of none other than the Empire State’s senior senator, Charles Schumer. The bad news is that now our junior senator is getting in on the act, betraying the free-trade ideals of her husband’s presidency while she’s at it. The even worse news is that poor New Yorkers, already faced with exorbitant milk prices, might have to pay more for “cheese foods,” too.