THE ADMINISTRATION abhors heavy-handed federal intervention in local affairs -- except on some issues. In Indianapolis the Justice Department is now intervening in the most delicate of local matters, the racial composition of the police and fire departments. Over the objections of the city's Republican mayor, it is asking a federal court to order the rewriting of a 1978 consent decree in which the city pledged to raise "the black composition" of the two public safety departments until their makeup "more nearly reflects the racial composition of the work force of the city." To accomplish that, the city agreed to reserve for "qualified black applicants" for as long as necessary at least 25 percent of the places in "all future police and fire training classes." A similar consent decree was entered in 1979 affecting women; the Justice Department is also attacking that.

The department is acting on the basis of a Supreme Court decision last year in a Memphis firefighters case. The assistant attorney general for civil rights, William Bradford Reynolds, contends that the court in this case outlawed all affirmative- action plans containing explicit numerical goals. His view of the case is sharply disputed. The issue in Memphis was layoffs -- whether race could be given more weight than seniority in deciding whom to keep and whom to let go at a time of retrenchment. The court said seniority should govern. But seniority rights have a special place in the law, and civil rights groups say the court did not mean its decision to extend to such other areas of affirmative action as hiring and promotion. Some federal courts have also taken this view since the Supreme Court spoke.

Mr. Reynolds sees a principle at stake. He believes the law should be colorblind. There are good arguments to make on this account in certain cases, and not everything ever undertaken in the name of affirmative action is right. But the Supreme Court itself has said that race can be taken into account in overcoming the effects of past discrimination, and Indianapolis is no great symbol or path breaker in the affirmative-action debate. Its mayor, William H. Hudnut III, says its police and firefighters hiring plan was working peacefully and well, and "if we want a higher standard of hiring than what the Justice Department requires, I don't understand why they can't let us do that." Blacks make up about 18 percent of Indianapolis' work force. When Mayor Hudnut took office in 1976, they made up about 10 and 8 percent of the police and fire departments, respectively. Those figures are now 14 and 13 percent.

Officials in this administration sometimes voice astonishment that their record is viewed as anti- black and anti-civil rights. If they genuinely wonder at this, they should look to Indianapolis. It's not just that the department is on the wrong side -- which we think it is. The department under Mr. Reynolds is trying to make law on affirmative action -- to force its view of the law on the country in advance of the courts. It is welcome to do that in future cases, to argue for whatever result it pleases. But to reopen settled cases on such a weak basis is to threaten social peace for the sake of ideology. The Justice Department should go home.