The answer, conceivably, is: Paul Laxalt. The question is the last line of an old story that sums up the mood of much of the electorate:

A man walking along a cliff feels the ground crumble beneath his feet. He manages to clutch at a root extending from the face of the cliff, which saves him from falling to certain death on the jagged rocks amidst the crashing surf far below. But he cannot climb back to safety, so he shouts up: "Is anyone up there?" A voice -- the voice of God -- fills the sky: "Have faith and pray. If you have sufficient faith and pray properly, you may let go and you will fall lightly as a feather, landing unhurt amidst the rocks and surf." The man looks back down at the rocks and surf, ponders the offer, and then shouts up: "Is anyone else up there?"

When the electorate surveys an early list of presidential aspirants, it usually sinks into an "Is anyone else up there?" mood. The electorate has achieved a remarkably comfortable relationship with today's president and cannot see a substitute on the horizon.

But waiting in the wings -- not just waiting, actually pacing restlessly and pawing the dust -- is Mr. Conservative's First Friend, Paul Laxalt, senior senator from Nevada.

Nevada has about 303,258 registered voters, a group smaller than the crowd that passes through Chicago's O'Hare airport on a busy day. But at this stage in the presidential scramble, much smaller numbers can matter more. There are, Laxalt says, about 5,000 Republican leaders crucial to the nomination process, and he, because of his long association with Reagan and his service as national GOP chairman, has a long leg up in dealing with them.

If Laxalt enters the race -- and a conversation with him leaves little doubt that he is inclined to -- his entry could have two immediate effects. It could considerably complicate Jack Kemp's fund-raising, which, naturally, starts at a marked disadvantage relative to the vice president's. However, Laxalt's entry also could wash off whatever sheen George Bush has by virtue of being perceived as the president's preferred choice. Laxalt and Reagan became freshman governors of contiguous states in 1966 and have remained politically and personally close.

Laxalt's placid temperament is a close approximation of the Reagan persona with which the country is comfortable. Reagan is going to be a hard act to follow, and it may be especially risky for Republicans to follow with a similar act rather than something new. But if they want more of the same -- call the style Western ease -- Laxalt is the obvious choice.

By 1987, Laxalt will have retired from the Senate. He does, however, have two related problems. One is Nevada. The other is a libel suit he has filed in response to a newspaper article.

O, Nevada. Mario Cuomo thinks he has problems because he is an Italian American from New York and hence is vaguely tainted by imagined associations with unsavory elements. He should try being a public official from Nevada, a state in which the arrivals of Howard Hughes and the Teamsters' pension fund were considered stages of moral uplift.

Laxalt's libel suit springs from a long article published in November 1983 in the Sacramento Bee. It alleged that substantial sums were skimmed from receipts of a casino in a Carson City, Nev., hotel then owned by Laxalt. It is not easy to say what, precisely, the article says Laxalt was culpable of knowing or doing. But some analysts think it is especially easy to win a libel suit against articles that seem too clever by half, articles written in a way that seems suspiciously pre-lawyered by people who may have thought they were on thin ice.

Laxalt is confident of at least a "Sharon verdict" -- a judgment that the article was false. He thinks he also will win on the question of malice. If he does, he probably will promptly enter the scramble for the Reagan succession. He thinks the 1988 task is to prove the Reagan years were not an eight-year aberration produced by Reagan's charm.

He does not disguise the fact that he thinks none of the active aspirants has shown, or seems likely to show, the required combination of political appeal and ideological steadfastness. Laxalt is especially impressed by the number of people who, although publicly supportive of Bush, are urging him to run.

He thinks about this at his cabin out at High Knob, Va., an hour and a world away from Washington. He calls it "Camp David without fences." He may soon ask the electorate to fence him in.