Walter Mondale's campaign in its dwindling days gives off an aura of wistfulness -- of "We don't expect much, certainly not victory, but can't we please just have one major state?" While winning, finally, the respect of a nation that suspected him of being an insider unwilling to plead his case hard and long before the voters, Mondale seems destined to go down as one of the great loser presidential candidates.

His immediate predecessors in that category, Barry Goldwater and George McGovern, were both rebels who captured their parties by attacking from the flanks, and their losses could be explained that way. Mondale, though, has managed to disprove Richard Scammon's and Ben Wattenberg's sturdy dictum that the center always wins in presidential elections (unless you define center tautologically, as whoever's more popular). Within his own party, it will take about three days after Nov. 6 for a mythology to spring up of Mondale as a last-hurrah figure, the symbol of the death of industrial-strength Cold War liberalism.

But for a weak challenger who never really got near the champ, Mondale has had a surprising impact on the future course of the government. Goldwater's and McGovern's defeats were taken by the incumbent presidents who beat them as signs that their views could be utterly dismissed. Ronald Reagan, on the other hand, not only did not make the election the ringing affirmation of conservatism that his old fans wanted it to be; he moved noticeably on nearly every important issue as a direct result of prodding by Mondale.

The most famous case is his ever-more-fervid denunciations of taxation, which came directly in response to Mondale's promise to raise taxes. But this was atypical in that Reagan established a position opposite from Mondale's; more often, he moved away from a time-honored conservative line of thinking when Mondale took off after it.

For most of the years he has been speaking publicly about politics, Reagan has been skeptical of Social Security; now he has promised in person never to cut it for present recipients and, by proxy, never for future recipients either. Reagan has never spent much breath on arms control agreements, but presumably this was because he was skeptical that they really make the world safer; now, however, he has promised repeatedly to enter into talks with the Soviets, and will not let Mondale appear more committed to arms control than he is.

It's a smaller example, but in a way even more surprising, that Reagan portrayed himself in the second debate as having been an opponent of Anastasio Somoza and a supporter of the revolution in Nicaragua. Again, it's a longstanding conservative argument that we should support dictators loyal to us over "national liberation" movements that soon won't be, but Reagan didn't want to say that. In the same vein, instead of defending cuts in poverty programs, he implied (and George Bush said outright) that he had increased them instead. Instead of criticizing environmentalists, he portrayed himself as one of them.

Reagan is notable among politicians for the extent to which he keeps his promises -- remember how surprised everyone was when he really did try to cut taxes, increase defense, cut social programs and balance the budget, all at the same time? Walking past the White House these days, one can almost hear the sound of foreheads being smacked in frustration at what the boss has promised. Trying to cut domestic programs more, keep increasing the defense budget, watch helplessly (while professing optimism) as the deficits mount, and pull a treaty with the Soviets out of the hat is not going to be fun.

How was Mondale able to do what much friendlier figures (such as Howard Baker and Robert Dole) never could, namely, to get a stubborn president of fierce principles to budge -- not on the specifics, but in his fundamental views?

In every case, the connecting thread is that Mondale publicly accused Reagan of meanness or deceit -- the classic formulation being the one on taxes: "He won't tell you; I just did." Campaigns are conducted in public, so Reagan had to answer on his feet, especially in the debates.

Reagan obviously prides himself on being both nice and honest, and he loves to play the part of the good man unjustly accused. With his body and his voice, he communicates a perfect blend of innocence, hurt and gumption when it is suggested (his words, first debate) "that somehow I am the villain." His reversion to that role is more than just a tactic; the lesson of this campaign is that it's nearly a compulsion, causing Reagan to lose his self-restraint.

That seems odd, given our picture of Reagan as a happy man, almost to a fault. But remember that his conversion to conservatism came at a time in his life when he wasn't happy, and when the good man unjustly accused was, to his mind, exactly what he was. His wife had left him though he was a good husband, the studios wrote him off though he was a good actor, the communists went after him though he was a good union man. The passages in his autobiography on this period are poignant, but also self-pitying.

What Mondale did was stumble onto a way to touch the nerve. That Reagan reacted so strongly, and that others may have noticed how well the technique worked, may be Mondale's most important legacy.