NINETY-THREE million men and women voted for president of the United States.

Fifty-one men and two women will vote to select the next majority leader of the U.S. Senate. Obviously the two jobs are not of equal importance. But the choice the incoming Republican senators make on Nov. 28 will affect national policy in all sorts of ways over the next several years. And if the electorate is smaller, the suspense about the outcome is greater.

One reason is that there are five senators currently in the race, all with reasonable claims on the job. Another is that in this kind of contest senators don't like to make public commitments -- and the verbal commitments they do give often turn out to vanish. For the election is held by secret ballot, with the low man eliminated after each round. Finally, since several of the competitors hold or are in line for committee chairmanships, the choice has all sorts of ramifications for the various committees. Choose Bob Dole, for example, and you get Bob Packwood as chairman of the Finance Committee; choose Richard Lugar, and you get either Jesse Helms as chairman of Foreign Relations (though he promised the folks back home he'd keep Agriculture) or Charles Mathias of Maryland.

Inevitably the choice is described as an ideological one, and the contenders are characterized by positions they've taken on issues in the past. That's important but not definitive. The biggest problem facing the new Republican leader is that he will have a White House, reinforced by 525 electoral votes, inclined to move in one direction, and a constituency of 53 senators, 22 of them up for reelection in 1986, often with an incentive to move in another. Holding the senators together with each other and with the administration, or inducing the administration to move where the senators want to go, is a formidable task. The job requires not just parliamentary skill and political instinct, but plenty of hard work sifting out the views of the diverse body of men and women who make up the Senate majority.

Howard Baker did a masterly job of this. Those who seek to be his successor will surely promise to follow his example. They should remember it's not as easy as Mr. Baker made it seem. There was nothorities for the Reagan budget and tax cuts in 1981, for the tax bill of 1982, for the gas tax in the lame-duck session or for the Social Security reform of 1983. The decision that Republican senators will make on Nov. 28 is an intensely personal one. They ought to remember that the job of a leader is to make order out of chaos, to prevent the ever-present possibility that nothing -- not even a budget -- will get done.