ON JAN. 20, 1985, when the next president is sworn in, I will be a private citizen. My concerns will be less those of a Democratic Party functionary and more those of an average American who cares for his country.

As a loyal member of the Democratic Party, I believe Walter Mondale should be elected president.

As a private citizen, nothing is more important to me and my family than his election.

Before making the case for his election, let me for the sake of fairness touch on those areas where the case is neutral.

First is the question of character: Walter Mondale is a genuinely decent person. As a neighbor of the Mondales in Washington, our family had the chance to see the Mondales "up close and personal," as they say. What you see on TV is the real Walter Mondale -- no pretense; no manipulation; no distance from real people and real problems. As president, America would love him.

Ronald Reagan is a genuinely decent person, too. Or so I'm told. Although I have had little direct contact with him, that is the opinion of those who have dealt with him first-hand.

I also have to acknowledge that the Reagan years have not been without import. Before 1980, we Democrats had a reputation as "tax-and-spend" enthusiasts. We failed to set priorities among social programs. Business was regarded with suspicion. Government was considered omniscient.

The country rebelled against that mindset and Ronald Reagan was there to catch the falling apple. The notion that government is the solution to all our problems has been rethought. The president has received credit for restoring respect for the private sector. That part of Ronald Reagan's record is secure.

The election of Nov. 6, however, is not about reliving the past or sending a four-year-old message to the Democrats. Rather, it is about who has the qualities of leadership to shape the future in a way that will leave our children more secure. It is not about where we have come, but rather where we will go.

In a number of important policy areas, the last four years have pointed the direction in which a second Reagan administration will go -- backwards.

Whether one considers the environment, civil rights, women's rights or investment in our human potential, the contrast between Ronald Reagan and Walter Mondale is striking. In each of these areas, Mondale will provide the forward-looking leadership these issues deserve.

And what about the president? To take one example, if there is one issue on which both parties worked together and were equally committed during the '60s and '70s, it was the environment. Bipartisan majorities in Congress passed landmark legislation to cleanse our water and air and protect our natural resources.

What has happened in the last four years? Enforcement of those laws has been halfhearted, where it exists at all. The Reagan administration has tried to lease nearly the entire U.S. coastline for oil and gas development without proper safeguards. The Environmental Protection Agency's operating budget has been cut almost in half. And to guard our precious natural resources, President Reagan chose James Watt and Anne Burford.

Or consider civil rights. Examples of administration efforts to erode progress in this area are legion: The derailment of the Civil Rights Act of 1984; support of tax exemptions for segregated institutions; footdragging on the Voting Rights Amendment; official ridicule of comparable pay for comparable worth.

Or consider investment in our human potential, so critical to remaining competitive in tomorrow's world. When it comes to child nutrition, day care, student financial aid, loans for small business, the Reagan record has been one of knee-jerk rejection. Weapons alone do not a strong nation make.

The election of Nov. 6 is about the future. But it is about more than that.

Walter Mondale has said that he'd rather lose an election about decency than win one about self-interest. I don't believe the two are mutually exclusive. As a private citizen, it is in my self-interest to have Mondale as my president. Decency and self-interest go together here.

First, there's the effect of the deficit on my self-interest. To the average voter the deficit is but an irritant. The rest of the economic news is better. The bread and butter issues appear to go the president's way.

But there's a problem with that. The real self-interest question for me and the real question about the economy is what happens after the election. Most important, for example, is what happens to interest rates. Treasury Secretary Donald Regan has said, and President Reagan has repeated, that deficits have no effect on interest rates. That's like saying that eating candy has no effect on the incidence of tooth decay.

The issue is not just that Ronald Reagan has signed up for $850 billion of debt.

The issue is not just that on his watch he is giving us a debt that will be equal to that of all presidents before him combined.

The issue is not just that the debt will approach or exceed $200 billion a year for as far as the eye can see.

Nor is the issue just that the interest alone on the debt will exceed $200 billion by the year 1989.

The real issue is that he doesn't think we have a problem.

The real issue is the virtual unanimity among economists, businessmen, farmers, homebuilders, etc. that real interest rates (the difference between prevailing rates and inflation) are higher than ever and Ronald Reagan doesn't think so.

The real issue is that these interest rates are overvaluing the dollar, rendering our exports noncompetitive and Ronald Reagan doesn't seem concerned.

The real issue is that the cost of capital in the United States is far higher than in Japan because, in part, of our high interest rates and Ronald Reagan doesn't think it is serious.

What does Ronald Reagan think? He thinks we should have a balanced-budget amendment.

If he really believes that, doesn't it make sense that he should do the obvious -- i.e. submit a balanced budget? That would be leadership. Yet he doesn't do that.

Why doesn't the president at least endorse the idea of a federal budget freeze so that the deficit won't get any worse?

Why not keep the free-spending Pentagon, which will need another $40 billion increase next year, under some fiscal constraint?

No balanced budget is submitted.

The federal-budget freeze is actively opposed.

Defense expenditures run out of sight.

And yet Ronald Reagan claims that he is for a balanced-budget amendment -- just like Bonnie and Clyde were for gun control.

Say what you will about the history of the Democratic disregard of deficits. The fact is that the highest deficit ever under a Democratic president -- Jimmy Carter -- was $60 billion -- a deficit that today would be hailed as a true miracle.

But more important, consider the key question of leadership on this issue. Walter Mondale knows we have to address the deficit issue, and he has attacked the issue head on. That takes leadership.

Although I supported John Glenn during the primaries because of questions about Walter Mondale's leadership ability, Mondale's acceptance speech at the Democratic convention provided a clear and convincing answer to my questions. I had always known that Walter Mondale is knowledgeable, that he is compassionate, that he is a problem solver.

But I learned that night that he is also tough. He has had the courage to speak the truth and propose a real remedy -- a tax increase. He has proposed funneling those revenues into a trust fund to reduce the deficit. He has promised to veto excessive spending.

Whether you like his proposals or not, Walter Mondale has at least reached Step Two -- offering a real solution. Step One is acknowledging the problem. Ronald Reagan has yet to get there -- and is publicly committed never to getting there.

Second, it is in my self-interest to have a Supreme Court that reflects the basic commitment to pluralism and tolerance that makes America the home of the free.

Everyone is aware of how the aging process is overtaking some of the more progressive and more centrist of The Brethen. In the next four years, three, four, perhaps five vacancies will almost certainly occur on the nine-member Court. Ronald Reagan, free in a second term from re-election considerations, will follow his basic instincts and his ideology. And when he applies these to Supreme Court appointments, we will witness a profound shift in that institution.

What if the delicate balance of the present court is destroyed by the appointment of several extreme conservatives? We would then be faced with an ideologically committed majority, intent upon reversing decades of precedents and legal tradition. More important, for perhaps the next 20 or 30 years the Supreme Court would reflect the thinking of Jerry Falwell and the apostles of the New Right.

Take abortion as an example. Abortion is an exceedingly difficult social and moral issue. People on both sides are truly committed to their positions and that commitment is real, honest and legitimate.

The slenderest of majorities on the court now upholds a woman's right to an abortion. Suppose the membership of the court were to change to a pro-life majority and abortion were to be banned. The will of the vast majority of Americans that abortion should be a matter between a woman and her physician would be discarded in a frenzy of ideological excess.

Abortion is just one example of the ultra-conservative agenda. Issues like racial justice, work safety, privacy, rights of the accused, freedom of speech and of the press will all be under assault.

Tread carefully here, America. Ronald Reagan would trample through these delicate fields like a wild bull.

Walter Modale would not. He would be respectful of our traditions. He would accept and foster the judicial pluralism that has protected our personal freedoms. Surely in this area, too, it is in my self interest to vote for Walter Mondale.

Third, there's arms control -- the obvious fusion of decency and self interest.

Ronald Reagan says he's for arms control. I believe him. I have no doubt that he's for arms control as he understands the concept and its purpose.

Instead of a means to enhance our security, he sees it as an instrument for dominance over the Soviet Union. Instead of a reason for sincere and careful negotiations, he sees arms control as a game to play while we build up to military superiority. More than just "peace through strength," he seeks a moral reckoning with a biblical sort of adversary. It may be satisfying for the president to think of an outright victory, but against an opponent armed with thousands of nuclear weapons, such notions are futile and dangerous.

Ronald Reagan says that the Soviets are contemptuous of any American weakness and will exploit that weakness in a flash. He's absolutely right.

Ronald Reagan also says that the Soviets will stand in awe of our new power, mouths agape, and acquiesce to a treaty enshrining American military superiority. What an extraordinary expectation!

Reverse roles for a moment. If the Soviets were to announce that they were going to achieve military superiority and only thereafter deal with us on arms control, what would we do? Would our jaws go slack? Would we beg for understanding? Would we ask where we could sign? Obviously not.

Now if the Soviets are hardline, paranoid and rapacious, why do we assume they are going to act like whipped dogs? They will not.

Ronald Reagan has never mastered the fine details of armaments and nuclear negotiations. He has never met with a Soviet head of state. He has never negotiated a treaty with them, and he has opposed every arms-control treaty that presidents -- Democrat and Republican -- negotiated before him.

So if he believes in arms control, where is the evidence? Consider, for a moment, Reagan's starting team. Casper Weinberger is the quarterback. He is always on the offense and likes the big weapons -- particularly attracted to the long bomb. The fullback is Ed Rowny. He can't carry the ball, but is excellent at blocking. At right end, right tackle and right guard are Fred Ikle, Richard Perle and Ken Adelman. There is no center and no left anything, although Paul Nitze plays lonesome end.

With such a team at his side, how will Ronald Reagan, who has not bothered to master the details of strategic doctrine, negotiate an arms-control treaty with the Soviet Union? Is he or Walter Mondale the man we should trust with the fate of the earth?

After four years of Ronald Reagan we are not one step closer to peace -- not one step.

Walter Modale will negotiate seriously with the Soviets. More important, he'll be a tough and committed negotiator because he knows what he's talking about. Most important, our children will grow up in a safer world.

I am leaving the Senate so that I can devote more time to bringing up my children. I dearly want to watch them experience life, to grow up, to partake of the wonders of what God has given.

Their lives are very precious to me. So are the lives of all children. They have decided nothing. They have hated no one.

They deserve a chance at survival. I don't believe that Ronald Reagan knows how to give them that chance.

I have three children. The oldest is but 10. I only wish I had three votes to cast for Walter Mondale.