This summer the homeless have at least one new comfort: they are being argued about. Seasonally, it is usually in the winter, when frozen corpses are carted off from alleys and rotted-out buildings, that attention is paid passingly to the short rations on which the homeless live and die. Then spring and summer come, and the camera of concern pans elsewhere.

In California last month, the Los Angeles County grand jury accused the state of ignoring a law that requires it to provide funds for homeless relief programs. The grand jury said the state is "shirking its responsibility."

In Queens County, N.Y., a group of Maspeth citizens heatedly protested a Board of Estimate plan for a shelter in the neighborhood. Noting the anyplace-but-here plaint that is commonly the largest turret when the comfortable build a political fortress to keep out the poor, The New York Times reported: "So far, efforts to expand (New York City's) shelter program have been blocked by community opposition wherever shelters have been proposed."

As the war on the poor continues to be waged from California to New York, no assault is more intense than the one unfolding in Washington. Judge Charles R. Richey, a federal jurist known for integrity who has often ruled against federal actions that damage the legal rights of poor people, is about to rule on the Reagan administration's decision to close a shelter for 1,000 people in downtown Washington.

The bums' rush is on. Last November the president promised to make that shelter "a model" to house the capital's homeless poor. The public may be conditioned not to take seriously the promises of politicians, but this pledge was different. It had the backing of Margaret Heckler, the secretary of health and human services.

If ever health care and human services needed to be delivered, it was at this shelter. The facility, in an area of prime real estate a few blocks from the Capitol, is a human survival camp that contains all the detritus of life at the bottom. Conditions would be worse were it not for the volunteerism of Mitch Snyder and the Community for Creative Non-Violence. With not a day or night off, its members have been housing and feeding people for nearly 15 years.

From the beginning, the promise of Reagan was not a difficult one. The administration would merely provide the funds and architectural plan to make the property livable. The building was already federally owned. This is the administration that four years ago said that the government must do less and private volunteer organizations more. Snyder has been the model Reaganite. He has taken no government money. At the shelter he oversees a staff of 35 volunteers, 30 of whom are the rehabilitated whofirst came in from the streets. It has been the Community for Creative Bootstraps.

Republicans cherish Snyder so much that Mrs. George Bush had him to the vice president's mansion last year for tea and cookies and a pleasant chat about the homeless. Mrs. James Baker came to Snyder's sickbed last October when he was on a to-the- death fast to pressure the administration to deal with the people on the streets.

That was when the "model shelter" pledge was made. The philosophical issue before Judge Richey is whether a presidential promise means anything. But courts deal in laws, not philosophies. The dealing should not be a strain. The Supreme Court, in a June 1983 decision against the Department of Transportation when the department shifted its position on requiring passive restraints for automobiles, said that "an agency changing its course is obligated to supply a reasoned analysis for the change."

This is missing in the case of the model shelter. HHS has now submitted architectural plans that Snyder, in something less than the language he reserves for tea time, dismisses as worthless. Benjamin Forgey, the architecture critic for The Washington Post, had similar views. He wrote that "the administration's so-called plan for the shelter -- three sheets of paper showing the most minimal disposition of various functions -- is as stupid and brutish as the CCNV (plans) are intelligent and humane."

Congress has never passed a Presidential Promises Act, but something better is available: the Administrative Procedure Act. In this case, a commitment by a Cabinet officer has been made. Either the procedures for fulfilling it are being followed or they aren't. The legal issue is about two- timing.

Federal involvement in homelessness is minimal. Instead of facing up to that, the Reagan administration is now attempting to make Mitch Snyder the problem, casting him as an opinionated madman who would find fault with a Taj Mahal for the poor.

Snyder's opinions aren't the problem. It's his convictions. When you live among the powerless and outcast poor, and serve them faithfully as Snyder has done for a decade, you tend to develop a conscience. That leads to convictions. One is basic: A promise means something. To the homeless at the shelter, Reagan's promise could mean everything.