RICHARD S. SCHWEIKER now leaves the most exasperating job in Washington. He has resigned from the Department of Health and Human Services to join the life insurance industry, ending a long and useful political career. It was an unlucky time to be secretary of HHS, for the two great overriding issues there--the financing of Social Security and the restraint of health care costs--were both placed beyond his reach. His department could, and did, send volleys of recommendations to the White House. But neither of those billowing quarrels lent itself to a quick, decisive solution. The president referred Social Security to an independent commission that now seems to be in the final stages of working out a compromise of its own. The perennial campaign to hold down hospital costs seems, for the present, to have sunk from sight altogether.

As secretary, Mr. Schweiker's greatest service doubtless lay in his careful responses to the unremitting pressure from the White House to keep cutting the budget. His department includes much of that small fraction of the federal budget that goes neither for pensions nor for military spending, and consequently is most vulnerable to budget-cutting raids from the Office of Management and Budget. In particular, he strongly defended the federal funds for health and medical research. There he was certainly upholding the more enlightened definition of the national interest.

Margaret M. Heckler, who is Mr. Reagan's choice to succeed him, will, if she is confirmed, inherit the duty of standing sentry at the doors of HHS against the budget raiders. The department carries much of the federal responsibility for the basic minimum of aid to the very poor--and for those people who are suffering most severely from this deep and prolonged recession. The amounts of money are small in comparison with the gigantic outlays for Social Security and Medicare, and the names of the programs are not always familiar. They are not defended so vigorously as the larger and more widely distributed benefits. They are things like the child welfare grants, Medicaid for the poor, supplemental security income for those whose Social Security is too little to feed them--aid delivered in small amounts to people with no other resources whatever.

Mrs. Heckler, an energetic and capable lawyer, will bring to the department the considerable skill and experience she acquired in 16 years in Congress. She will need them.