At the third Ford-Carter presidential debate on Oct. 22, 1976, columnist Joseph Kraft asked the first question. And it was a good one, put to both men: "As you look ahead in the next four years, what sacrifices are you going to ask the American people to make?"

In his answer, which probably surprised very few in the audience, Gerald Ford spoke of the sacrifice required in preserving the peace, which would mean an increase in defense spending. Ford's challenger charted a different course. "Well, I might say first of all," began the Democratic nominee, "that I think in the case of the Carter administration, the sacrifices would be much less."

With one sentence, Jimmy Carter revealed how very much he did not understand about the party he then led or about the people he then sought to lead. Most Americans, including most Democrats, regard sacrifice as an admission price for citizenship and regard themselves as good citizens. Our presidents are leaders who, for the common good and for a better future, ask us to sacrifice. But Jimmy Carter did not see it that way, and neither, apparently, does his successor, Ronald Reagan.

Throughout his successful 1980 campaign, Ronald Reagan's public message was exceptionally consistent. He offered voters a rose garden of reduced inflation, disciplined government and stronger defense. All were to be underwritten by a 33 percent, three-year tax cut. Reagan offered the economic equivalent of the Hot Fudge Sundae Miracle Diet. Everyone has seen the type that promises a slim figure for eating three or more of those ice-cream delights every day. This time, instead of flat tummies, folks were guaranteed ouch-less prosperity. All that earlier talk about there being "no gains without pains" and all that cold-shower school of economics were hopelessly outdated. The supply-siders were in, and all mention of blood, sweat or tears was decidedly out.

In fact, the story goes, in one of the scrimmage sessions for his campaign debate with President Carter, Reagan was asked what sacrifices he, as president, would demand of the American people. Reagan's response was reportedly unresponsive. Explained one of those coaching the Republican candidate: "His mind just doesn't work that way."

Margaret Thatcher's mind does work that way. The British prime minister's popularity figures are only marginally less disastrous than the British economic numbers. But there is a major political difference between the two conservative leaders. Margaret Thatcher offered and promised the British people, before she was elected, difficult and substantial sacrifice. In the midst of her troubles, Thatcher's past candor now sustains her within her party.

Reagan never similarly prepared his constituents for the harder times that appear to have arrived and more of which seem to be ahead. It may now be too late for the president to adjust his message, even if he chooses to do so. Voters, by margins of up to 2 to 1, see the Reagan policies as favoring the very rich over average working people. This makes any presidential appeal to sacrifice that much more difficult.

Reagan's reluctance to include any political castor oil in his 1980 prescriptions seems to be haunting him less than a year after his historic landslide victory. According to the Gallup Poll, Ronald Reagan's job rating by the American people is lower in October 1981 than Jimmy Carter's was in October 1977. Carter's was then 59 percent favorable to 24 percent unfavorable. Reagan's most recent Gallup scores were 56 percent favorable to 35 percent unfavorable. In that same Gallup survey, for the first time, Reagan received negative marks for his handling of the economy and inflation.

At the time of the survey, the Reagan tax bill had become the law of the land. But nirvana was not yet here. And the president, unlike the prime minister, had not told people to be patient or self-denying. By the different politics of Jimmy Carter and Ronald Reagan, sacrifice was not something leaders asked of the American people. Both men were wrong in their reading. Americans will sacrifice as long as that sacrifice does not appear to be selective and is required across the board.