To absolutely no one's surprise, Marion Barry has officially informed the capital city of his availability to continue as mayor for another four years. Any pollster in town will tell you that right now it's a likely prospect, too -- which is something to worry about. We're not talking here about whatever ultimate decision Washington's voters make this fall, but about the absence of an organized challenge to an administration that is by no account perfect -- that in fact has failed on a number of important fronts.

With no well-known strong opponent jabbing at the weaknesses of the city administration or proposing improvements, Mr. Barry's greatest enemy -- and everybody else's -- is complacency. That's why it is important to concentrate on the failures of the city government as legitimate campaign issues -- and not as fuel for any racist strain of critics in Congress or temporary residents who typically roll their eyes and mutter with a snicker, "Oh, the D.C. government" at every turn. The list is not small, either. And the people who are being hurt most are not the well-to-do or those with the most effective means of making their complaints known. On the contrary, they tend to be those in this city who live in substandard housing; in no housing at all but in a sorry supply of shelters; and in the jails and prisons.

Housing was in bad shape four years ago, when Mr. Barry last ran. Today, the U.S. secretary of housing and urban development has found this city's housing program so mismanaged that he has directed one of his top officials to step in and shape it up. Federal officials cite millions of federal housing dollars that have gone unspent while thousands of housing units remain unfit for habitation and 11,000 people wait to enter public housing. Mr. Barry says he welcomes federal assistance -- but what about old-fashioned local initiative?

And what about the homeless? The federal government and private groups are groping -- and not all that successfully -- with ways to shelter those who cannot shelter themselves. Mr. Barry's chief contribution has been to watch from the sidelines and join in taking credit for what little others have been able to accomplish with great wasting of money in the process. It will be warm from now until election day, but the homeless will still be here when winter comes again. Will they be any better off -- and if so, will Mr. Barry have helped to make them so?

There may be less pity for those who are in the jails and prisons, but their treatment, too, must be humane. Fifteen-plus years of legal battling and the city's failure to act by building new facilities and responding to court orders have created an overcrowding that cannot be left to continue for even one more year, to say nothing of four. Mr. Barry says he's on this case, and has just made some good proposals with a vow to make them stick. But given past history, he will need holding to it.

There are still other programs that have been bungled. Above all, there is a matter of public trust -- and this takes in all incidents of corruption at city hall. Marion Barry is right to address this subject in his campaign, but voters should not hesitate to raise the issue at every turn. What steps will he take to set a stronger tone for integrity, honesty and responsibility throughout the ranks of his administration?

Mr. Barry may campaign smugly and win nonetheless. But it would be a costly victory for the constituents he professes to have served so well.