The Reagan administration has under study what could be its most regressive step on civil rights in five years in office. Circulating within the Justice Department and the White House is a proposed revision of the executive order on which is based the government's least known but possibly most important civil rights enforcement program. This is the affirmative action program quietly run by the Labor Department for federal contractors. It covers perhaps a fourth of the national work force, and extends to almost every major company and industry. To do business with the government a company must have affirmative action plans. A large company must show there is a reasonable relationship between the racial and other characteristics of its work force and the makeup of the work force at large from which it draws.

Opponents within the administration, said to include the attorney general, Edwin Meese, and the assistant attorney general for civil rights, William Bradford Reynolds, would eviscerate the order by stripping out the racial and other statistics now used as reference points. An excerpt from their proposed rewording is on the op-ed page today. So are some very different views of the matter; one is the view of the Supreme Court.

Those arguing for the more detached approach say it is the only correct one for the government to take: the government must be colorblind. We sympathize with that. We agree as well that affirmative action can and sometimes has been taken too far, to the point of strict racial and other quotas. But the proposed position goes too far as well, in the opposite direction. It places ideology above reality; it pretends as if there is no past.

This proposal, which would effectively destroy the government's ability to stop scrimination in taxpayer-financed jobs, was not sought by industry. "We've gotten used to it, frankly," a spokeswoman for the National Association of Manufacturers said of the present rule. From the other side of the table, the executive council of the AFL-CIO has said a weakening of the rule would be "a giant step backward in the fight against employment discrmination."

Twenty years of affirmative action by the government, unions and private employers have brought about dramatic improvement in the lot of minorities and women in the work force. The federal requirements have never involved quotas -- that is a straw man -- and they have been accepted in every segment of the economy, even by those most resistant at the start. The objective has been a level of fair employment that will make all goals and timetables unnecessary. But that day has not yet come. The proposed new order would gratuitously disturb a program that, for now, is doing moe to unify society than divide it. The program should be left alone.