As Congress prepares to conclude its final four weeks of the remaining regular session, we have begun a legislative version of the old TV show "Beat the Clock." The question is whether Congress will enact the Simpson-Mazzoli immigration bill before it adjourns.

The few remaining legislative days may provide the last feasible opportunity in this decade for Congress to act on urgently needed immigration reform. And, just as important, the outcome of this legislative exercise may answer the larger question of whether Congress is still capable of adequately dealing with any of the urgent national issues of the day.

Currently pending before a House-Senate conference committee is a carefully balanced and comprehensive immigration reform package, representing the bipartisan efforts of private citizens, members of Congress and four presidents. Few bills have received the devotion of effort and scrutiny that Simpson-Mazzoli has. Not only has the concept of the measure evolved from a presidential commission to hearings, markup and debate of committees in both houses during two consecutive congresses, it has also withstood repeated and varied attempts to kill or dilute it.

We have come much too far on the road to immigration reform to fail once again in the waning days of another Congress. Morever, should the exhaustive legislative investment already expended be in vain, policy makers will face an even greater Pandora's box. The alternatives to this substantive reform of our immigration laws are largely untenable.

No member of Congress can defend the status quo on immigration. The present situation is neither in the national interest nor in the interest of those undocumented persons who all too often find themselves beyond the protection of our laws, afraid to report crime or seek medical assistance.

The option of increasing enforcement alone is similarly deficient. It is simply not feasible to surround 5,000 miles of border with enforcement personnel. Any return to a mass deportation such as "Operation Wetback" of 1954 would almost certainly entail gross violations of civil liberties and, I fear, would forever scar the fabric of our society.

Additionally, I do not believe the American people would tolerate house-to-house searches and neighborhood sweeps attendant to any true effort "to round up and send home" all the illegal aliens now in the United States.

The suggestion that increased outlays on foreign assistance is somehow an answer in itself is also insufficient. As worthy as I know the goal to be, assisting developing countries in this hemisphere is a long-term proposition. Yet, we must also act in the short-term interests of the United States. While it is truethat "sending countries" contain so-called "push" factors (such as poverty, lack of educational opportunity, etc.), those seeking to leave stifling economic conditions must have a place of ultimate destination. It is primarily the better economic opportunities in the United States that serve to attract those with a desire to improve the quality of their lives.

Some have recently gone so far as to suggest that Congress has a further option of completing action on Simpson-Mazzoli in a lame-duck session after the November election or of reviving the bill next year in a new Congress. But let's not forget both approaches have been tried before -- and recently. The lame-duck consideration of Simpson-Mazzoli during the 97th Congress -- just two years ago -- resulted in opponents' offering some 300 amendments, which forced the bill to be killed as legislative time conveniently did not permit its meaningful consideration. At that time, there was the suggestion that we start afresh in the upcoming Congress. Well, since then, nearly 2 million people have been apprehended by the border patrol (and at least 4 million successful illegal entries have occurred).

Let me be clear: nothing can be gained from further delay. The moment of legislative decision has arrived. It is now time for Congress to fulfill its legislative responsibility.

Four administrations of both parties and the Select Commission on Immigration and Refugee Policy have agreed that it is necessary to "demagnetize" the attraction of employment in this country if we are to have any chance of meeting the challenge of uncontrolled illegal immigration.

In this regard employer sanctions constitute the heart of the Simpson-Mazzoli measure. This provision provides that penalties be imposed on those who knowingly hire, refer or recruit undocumented aliens for employment in the United States. Additionally, the bill contains numerous anti-discrimination provisions that will ensure that it is applied in an evenhanded fashion regardless of whether an individual is blond-haired and blue-eyed or dark-haired and brown-eyed.

In those instances where undocumented workers take jobs that domestic workers are unwilling to fill (as is often the case with respect to agriculture), both the House and the Senate versions contain variations of a program to allow agricultural workers into the United States if and only if there is a demonstrated shortage of domestic workers.

The adjudication provisions of the bill are designed to alleviate the abuse of our laws now possible through procedural delay by those who have no right to remain in our country. In addition, the independence and stature of the administrative process is increased by the legislation.

The Simpson-Mazzoli bill contains a legalization program that would adjust the status of those who have established sufficient equities in our society. The House bill contains a Ja. 1, 1982, cutoff date.

By contrast, the Senate version of the bill contains a two-track approach whereby anyone who entered the country prior to Jan. 1, 1977, would qualify for permanent-resident status. Those who entered after that date, but before Jan. 1, 1980, would be eligible for permanent residency. Those in the latter category would have the opportunity to earn the right to become permanent residents within three years.

While it is my feeling that the House version of the bill is too loosely constructed on this point, the important concept of legalization, embodied in the language of the bill, should dispel the argument that it is is somehow nativist. This one-time act of magnanimity offers those who have become permanent members of our society, but are forced to live a sub- rosa existence because of their illegal status, the chance to become fully participating members of society.

Equally important as the need for substantive immigration reform is the question of whether Congress is still an effective institution and forum to deal with the complex and difficult national issues of the day. With the repeated delays in the consideration of the Simpson-Mazzoli immigration bill during the past three years, many wondered whether our legislative process had become captive to the will of affected interest groups rather than the national interest.

However, during the seven days of often emotional House debate over Simpson-Mazzoli in June, the House distinguished itself by demonstrating that, if given the chance, it could meet the challenge of completely addressing such a controversial public policy question.

While we are closer to meaningful immigration reform than we have been in years, much yet remains to be done to produce a conference report acceptable to both houses of Congress. The test of this Congress is whether the special interests will prevail in the remaining legislative days or whether Congress will address something that needs its immediate attention in the name of the national interest. If we are afforded a meaningful opportunity to deliberate, I am optimistic that a carefully balanced immigration package will become the law of the land.

Our country has prided itself on being a vast melting pot. The genesis of the Simpson-Mazzoli bill lies in the desire to allow the United States to continue its generous policy of immigration. However, it would do so by achieving one of the objectives of the Select Commission on Immigration and Refugee Policy report, that is, it would close the back door to illegal immigration so that the front door on legal immigration may remain open.