THE SIMPSON-MAZZOLI immigration reform bill, which has been passed twice by the Senate, is at a critical stage in the House. Five separate committees have considered the bill, four have issued reports and, predictably, the interests represented on those committees vary greatly. Agriculture, for example, wants to ensure the availability of foreign workers to harvest crops; Education and Labor has a primary concern for preserving the jobs of Americans. Now it's up to the Rules Committee to devise an orderly method for dealing with these diverse interests, organizing a plan for floor votes on all important issues, while at the same time foreclosing the kind of hundred-amendment nit-picking that killed the bill in the House last year.

There are fewer tha half a dozen major areas of disagreement on this bill, with two or three alternatives proposed in each case. The most important is employer sanctions, for unless these are preserved and made effective the main purpose of the bill will be destroyed. Disputes over record-keeping, penalties and potential discrimination can be settled with a few votes. Similarly, the date of the proposed amnesty for illegal aliens already in this country is easily determined. The question of foreign agricultural workers is a hot one, but the choices are clear-cut, the interest groups backing each alternative easily identified. Finally, in the category of major disagreements is the question of whether an overall ceiling on legal immigration should be imposed, as the Senate-passed bill requires. A single roll call can settle that straightforward and uncomplicated matter.

It would not be difficult for the Rules Committee to send the bill to the floor with either a time limit or a plan limiting amendments to these major areas. Immigration reform is badly needed and has been exhaustively studied in the executive and legislative branches and by a blue-ribbon select commission. Good momentum was achieved earlier this year when the Senate passed a bill, 76-l8. All relevant House committees have had an opportunity to review the bill and to propose amendments. If it is delayed through the summer, that momentum begins to erode. As election year approaches, action on this politically sensitive question becomes less likely. It's time for the House Democratic leadership to get the bill to the floor, and it's possible to do so under conditions that will allow debate and orderly decision without either chaos or stalemate.