SUPPOSE THAT the Reagan budget-cutting effort were to bog down completely now. That's not an impossible prospect, since the president has signaled at least a temporary loss of determination to make more cuts. Should the effort, then, be considered a failure?

By many measures the administration's effort to control the non-defense budget was a considerable success. Last summer's budget reconciliation worked changes that reach far beyond the $35 billion (no insignificant figure) in budget savings. One was arresting the aimless proliferation of special- purpose programs that had become standard operating procedure in Congress. See a problem? Set up a federal bureau--maybe even a department--and issue a volume or two of regulations to guide the counterpart offices at the state and local level. A lot of these little programs were gobbled up in the budget process, and, as a result, states and localities have at least somewhat more freedom to tailor federal programs to their special needs.

Only one big benefit entitlement program underwent major surgery. That was trade adjustment assistance--and it deserved it. But almost all the others--even veterans' programs and Social Security --got some needed streamlining. Eliminating redundant and unintended benefits can save big money over the long haul, and it makes the programs more acceptable to the taxpayer as well. Further progress along these lines is mostly a matter of better administration rather than of more legislation.

The results aren't final yet on the farm programs, but some curbs were placed on the most extravagant subsidies. Cracking the once impregnable farm lobby could pay off over time in a better-balanced farm policy--if the pressure stays on.

We don't want you to get the wrong idea: not all of the changes were benign; far from it. Job programs turned out, in retrospect, to have provided useful services to both communities and participants, and some substitute--preferably one with better links to the private sector--is needed. The working poor in general took much more than their share of losses, and their fate will need watching.

There is also much unfinished business. The job of sorting out federal and state responsibilities has only begun. Curbs are needed on cost-of-living adjustments in entitlement programs, and the runaway medical programs must somehow be controlled. The public-works dispensing machine is still in full operation--while many important public investments are neglected--and grant-in-aid formulas need an overhaul to direct funds to places where they are really needed.

Completing this agenda won't be easy without the convenient congressional cover provided by a fast- moving budget-cutting drive. If the administration can provide leadership for further progress of this sort, its budget-cutting program should not be judged a failure. A large budget deficit in 1984 will owe its existence much more to an ill-advised tax policy than to an inability to carry out a consensus for dismantling most of the federal government when that "consensus" never really existed.