DESPITE the tactics of President Reagan, Senate moderates from both parties managed last week to rescue the congressional budget process from stalemate. The struggle for a responsible budget is still far from over, but the prospect is at least somewhat brighter than it was a week ago.

The hero of the rescue mission was Sen. Pete Domenici, chairman of the Senate Budget Committee, who sets out his own view of the proceedings on the opposite page today. For more than two months he tried to satisfy the president's demand that the Senate follow the outlines of his big-defense, low- tax, big-deficit budget. Together with Majority Leader Howard Baker, Sen. Domenici pressed repeatedly but unsuccessfully for passage of a White House-endorsed resolution. Finally, late Thursday night, he switched his vote to assure passage of the alternative budget favored by Republican and Democratic moderates.

Although the moderates' resolution won by the slenderest of margins, it is far from a last-ditch compromise. Its general outline--holding the line on domestic spending, sustaining but moderating the defense buildup and gradually raising taxes-- follows the recommendations of such diverse groups as the nation's governors, leading industrialists and former Cabinet secretaries of both parties. It is also more responsive than the president's plan to the apparent preferences of the public. Opinion polls never showed much public support for the president's gigantic tax cuts, and enthusiasm for his massive defense buildup has waned.

The future of the budget resolution is still far from secure. First, the Senate must resolve its differences with the House, which, without presidential interference, passed its resolution in March. But notwithstanding substantial differences between the two resolutions, this may not be such a difficult task since the House resolution was constructed more or less with compromise in mind. The biggest stumbling block is the president. He has signaled repeatedly that he is quite ready to sweep aside the congressional budget process if it suits his immediate purposes.

If Congress adheres to a budget resolution it can frustrate the president in certain ways. It can force the appropriation committees to adhere to lower defense targets, at least in the short term, and it can require authorizing committees to make those reductions in entitlement programs called for in the resolution--but not the additional cuts sought by the president. But the president will still be able to veto unwanted increases in discretionary domestic spending, thus promoting his public image as a deficit fighter. And he can also veto the tax increases, which are far more important to future deficit control than the relatively small domestic cuts he seeks.

Forcing the president to accept a sound budget program will require a degree of bipartisanship that will be hard to come by. Congress is quite right in perceiving that no matter how responsibly it acts, the president will assign it the role of fall guy for what goes wrong and, at best, supporting cast for what goes right. But that's no reason not to try.