A GROUP OF concerned citizens paid us a high compliment the other day — by showing up to picket outside our doors. Nice to know our words are provocative enough to protest. Community and Postal Workers United was calling attention to what its members consider consider our unduly stringent view of the need for the Postal Service to restructure, especially by reining in the labor costs that account for 80 percent of its overhead.

In particular, the protesters repeated the oft-made argument that the Postal Service would be just fine, financially, if only Congress would relieve it of an annual $5.5 billion retiree health fund pre-payment. This deserves a respectful reply that fortunately can be brief. Postal Service data clearly show that the agency would still lose several billion dollars per year over the next half decade even without the pre-payment.

The retiree fund payment is not causing the Postal Service’s collapse. Its essential problem can also be stated simply: Because of technological change, the volume of first-class mail is plummeting, with no end in sight. Yet the Postal Service remains geared to the demands of a bygone age, burdened by a large network of little-used post offices and mail-processing centers, as well as a unionized work force of more than half a million people. The union labor contracts insulate workers from layoffs and guarantee them more generous health-care benefits than the general public, or even other federal workers, receive. This is not a sustainable system.

The protesters chanted: “Whose post office? The people’s post office!” But if they expect the people’s sympathy, they should also consider the plight of the people in their role as taxpayers. That’s who will inevitably be asked to pay the cost of propping up this system in defiance of economic reality.

Congress is working on the issue, though efforts thus far do not inspire confidence that lawmakers can or will overcome entrenched interest groups that benefit from the Postal Service status quo. The House’s relatively realistic approach would empower a commission to decide on closing postal facilities, on the model of the military base-closing efforts of recent years. It would allow the Postal Service to move more quickly to five-day delivery and bar no-layoff clauses in labor agreements.

The Senate, alas, has approved a bill that would shrink the postal workforce by up to 100,000 through $7 billion in early retirement packages but is otherwise tepid. For example, it requires the Postal Service to consider downsizing installations before closing them.

Even that exercise in foot-dragging was too much change, too fast, for some. Sen. Richard J. Durbin (D-Ill.) recently inserted language into a pending appropriations bill that would effectively prevent any move to eliminate Saturday delivery over the next two years, prohibit rural post office closures in the fiscal year that begins Oct. 1 and protect 11 processing facilities, including two in his state.

The Postal Service is burning down, financially speaking. Time for Congress to stop fiddling.