Americans traditionally are wary of placing too much power in the hands of their presidents, and for good reason. History has taught them that great power can be greatly abused.

The last two examples of great abuses of power are still fresh enough in the public mind to bear examining as another president appears headed for a massive triumph. If the form sheets hold true, on Tuesday Ronald Reagan will take his place alongside the two modern presidents who won the greatest of victories: Lyndon B. Johnson and Richard M. Nixon.

Johnson received the highest percentage of votes cast in a presidential election, 61.1 percent, while Nixon accomplished something never done before. He carried all but one of the states. At the least, Reagan appears likely to to begin a second term with a strengthened hand. He stands to win a greater electoral landslide and a greater portion of the popular votes than he did in 1980 .

For Reagan, no less than with his two failed predecessors, Johnson and Nixon, the question is what he will do with his presumed big victory.

Within a year after his great victory in 1964, Johnson had dispatched combat forces to South Vietnam for the first time, had sent bombers on missions over North Vietnam and, by that fall, had troops marching beyond the coastal enclaves through the elephant grass on search-and-destroy operations against the enemy. His presidency was doomed.

Within a year after his great victory in 1972, Nixon was engulfed in the Watergate crisis, his top aides had been forced to resign and were headed for jail and he had lost the ability to govern. His presidency was on the path toward impeachment.

In recalling those examples, I don't mean to draw an invidious comparison between the Johnson and Nixon tragedies and the possibility of similar calamity abroad and scandal at home in a second Reagan term. The point is how a president who wins so great a victory interprets his public triumph.

What does he want to do with it? How does he read his mandate? Where does he want to lead the country? And how does he intend to take it there? Has he let the public in on his plans? How does he want to exercise his newly granted power?

For Reagan, more than most presidents, these questions are far from academic. He has been the most ideological, and inattentive, of presidents. Given his cast of mind -- and, yes, his age -- the central question about Reagan especially revolves around how he reads his reelection.

Does it reinforce his belief that he was right all along, that he and the public have a special bond and mystical understanding about the correctness of his course? Does it strengthen his conviction to pursue a laissez-faire economic course and really embark on the social agenda of the so-called religious right? Does it embolden him to the greater employment of military force, as in Grenada, to combat the communists?

Reagan hasn't given us a clue.

His reelection campaign hasn't prepared the public for any actions to come, foreign or domestic. If he's given the voters a central message this year, it has been to expect more of the same: Don't worry, all's well. Let the good times roll. Other than in the broadest of platitudes, worthy of Calvin Coolidge at his simplest (Coolidge: "the business of America is business"; Reagan: "go for the gold"), he hasn't spelled out the necessity to do anything differently.

If there are no problems, and no need exists to make any changes, Reagan is home free, and so is the country. But if he has another agenda, or problems at home or abroad intrude, the public has no reason to know what to expect of his leadership.

Significantly, it's not only Reagan's critics and political opponents who have doubts about his possible course in a second term. Doubts about him exist strongly among the very people who intend to reelect him Tuesday.

Here, Mr. President, are typical examples of concerns some voters voice about you. Both are lifelong Republicans. Both voted for you four years ago. Both want to give you another four years. Both are worried that you might be too rigid. Both don't know what to expect from you.

A small businessman in Cedar Falls, Iowa: "I feel pretty positively about his presidency. The only area where he's not willing to look at alternatives is the deficit. The deficit is a major problem that affects us in the Middle West. He says, 'Oh, deficits. So what?' Four years ago, he thought deficits and inflation were the worst things in the world.

"He solved one of them, and we still have the other and it's far worse than it ever was. Well, $200 billion in one year is more than all of us in Cedar Falls could spend in a lifetime, no matter how high we lived. I think his personal problem there is that he believes so strongly in what he's doing that he cannot really accept an alternative. In this area, it's kind of like the first chapter in the Bible to him. There are no other chapters."

A big businessman on Wall Street: "I believe that Ronald Reagan's policies are the right ones. However, I hope we don't carry them to extremes. In my humble opinion, I don't think our tax cuts should have been so severe. There should have been more of a balance. The big error in the first four years was expecting the feedback effect from the tax cuts of greater growth and investments. That was just Pollyannaish. It just didn't work.

"The result of that miscalculation -- this idea that we're going to grow our way out of the deficits and grow our way out of it right away -- was a big mistake. Now we have this huge gap. And I hope that Reagan can somehow rise above the extreme right. Those people are the most worrisome to me. If that becomes the cast of mind in his second term, then we're in trouble because that mindset will not have us look objectively at conditions.

"One hopeful fact is he doesn't have to run again. He can say to the far right, 'All right, guys, rant and rave all you want and go with Jerry Falwell if you want. I'm now playing for the history books, and I don't need you for that.' That's my hope, but I'm afraid he won't. My fear is he's free to let his innermost feelings come out. And maybe there's another side to him that says compromising time is over. I'm afraid that to fulfill his strong beliefs he'll be more extreme. That's how I come out."

Of course, let's hope both their fears prove groundless. Reagan is equally free to play to the history books by being a conciliatory, moderating, pragmatic president who helps unify the country instead of dividing it, who talks sense instead of slogans to the people, who takes the lead on dealing with the really hard issues of our times -- arms control and restoring economic equity -- instead of letting them worsen by doing nothing.

But the problem is, as the people are about to vote, that no one today can tell how Reagan will act if he gets that strongest of presidential hands since that given Johnson and Nixon.