POLITICANS are always promising more than can be delivered -- and denouncing their opponents for not delivering it. Inflation of the possible is part of the game. The tendency to float a little above the facts increases as a presidential election approaches. This time it will be further magnified by the new budget rules as well.

The president, having submitted a budget, has already felt the new rule's effect. The programmatic departures he proposed were rightly characterized by congressional Democrats and others in the chorus as mostly gestures inadequate even to the limited number of national problems they addressed. But the Democrats are encountering similar difficulty. They know all the things the president didn't do -- they have the themes -- but lack the money to do them themselves. The crafters of this year's appropriations and (if there are any) other spending bills are likely to find themselves with the least maneuvering room of all. They will mainly be apportioning disappointment.

The budget rules create a maze of zero-sum games. The budget is compartmentalized, first into programs that are "discretionary," meaning subject to the appropriations process, and those that are not. The discretionary programs are further divided into defense and nondefense, and nondefense then into subcategories for each appropriations subcommittee.

The defense and nondefense subcommittees will each have maximum amounts that they can spend. The rather strange result will generally be to reduce competition across the broad functional lines of government -- defense money, for example, will not be available for domestic purposes, nor domestic money for defense -- while intensifying competition within each function. Education programs will be competing most intensively for funds with other education programs. The only way to increase funding much for Head Start will be to cut it for elementary and secondary education or college student aid (or in this case other social programs in the same subcommittee). A similar discipline will be applied to non-appropriated funds, mostly benefit programs, in the form of a pay-as-you-go rule: Any legislated spending increase must have a tax increase or legislated spending cut to match.

The president's budget made much of minor tradeoffs -- small increases offset by small cuts -- for which it was derided. But the congressional budget is likely to look much the same. Those, many of them Democrats, who say the country faces a social deficit alongside the budget deficit are right. But the social deficit can't be fought without the means. It's not a splashy thing to do, but the budget deficit has to be reduced first.