In the midst of tonight's NBC special on President Reagan's initiatives during his first year in office, there is a remarkable scene in which correspondent Judy Woodruff interviews a number of those attending a Republican fund-raising reception in Cincinnati. They are so smug, so sleek, so complacent with their white wine and hors d'oeuvres that the hoary old term, "fat cats," inexorably leaps to mind.

"A lot of people are going to have to tighten their belts," says one distinguished, gray-haired gentleman of Reagan's budget and tax cuts. "It's going to hurt a lot of people," agrees another, who also looks like a board chairman. "We're going to have to pay the price to get out of the mess we're in."

Yet another is asked, what do you think of Reaganomics? "I think his program is just fine," is the response. "It will succeed if people give it the chance to succeed."

You don't get the idea that these are people who are having to tighten their belts or who are being hurt. Across town in Cincinnati, however, NBC interviews some who are. These include people dependent on public health clinics whose federal funds have been cut and people who have been laid off in the recession.

"The government can live with high unemployment to fight inflation," says one young, unemployed worker. "But for us it's a very big sacrifice. It's a very high price to pay."

One woman who went off welfare to get a job and take college courses, but may have to quit in order to qualify for Medicaid, says angrily, "This is supposed to be the land of opportunity. It's not the land of opportunity. It's the land for the rich, and the poor can go to hell."

With this, NBC's crisp and incisive White Paper, "The Presidency and the Nation" (Channel 4 at 10 p.m.), dramatizes not only the scope and daring of the Reagan revolution but also its problems, for the citizens and the nation as a whole and for Republicans who hope to replace the Democrats as the dominant political party.

"Revolution" is not hyperbole in describing what Reagan proposes to do: halt, and try to reverse, the policies of the last 50 years, the growth of the welfare state in which the federal government assumed responsibility for the working of the economy and for the well-being of the poor, the powerless and the unfortunate. The numbers on Election Day a year ago clearly indicated that the American people, disillusioned about much of the working of their government and losing confidence in the Democrats' ability to manage the economy, were willing to give him the opportunity.

Nevertheless, a lot of people laughed when Ronald Reagan sat down to play, particularly when he promised to cut taxes, increase defense spending and balance the budget all at once. The NBC special demonstrates how hard, if not impossible, this is, and how difficult, if not impossible, it is to disengage from a welfare state that for half a century now has become part of the warp and woof of American society.

It opens by examining two issues -- the air controllers' strike and the attempts to cut taxes and government spending and balance the budget. Reagan's victory over the controllers is cited as a "textbook case of how to exercise presidential power." Reagan got on TV, defined the issue as one of upholding law and order, fired the strikers, decertified their union and won a resounding public relations victory.

You could argue, however, that he didn't beat much -- a weak union with little support and sympathy from other unions and whose actions apparently had little legal standing.

On the other issue, cutting taxes and spending and balancing the budget, narrator Roger Mudd, NBC's chief Washington correspondent, suggests that Reagan promised more than he could deliver because these are matters over which too many others have control.

"They the administration found that the president is much less powerful than we realize and less powerful than they like to admit," Mudd says. "He believed too much in the president's power and prestige and as a result squandered a great deal of it."

By late summer many in the administration, including budget director David Stockman, realized the impossibility of the task and by year's end most rational Republicans were tempering their early high hopes with the pragmatic realities of power and responsibility.

Yet their judgment appears to be that Reagan must keep the faith, keep the appearance of resolute consistency, or all he hopes to accomplish will be lost. Machiavelli counseled that the prince should combine the qualities of the lion and the fox, steadfastness with craftiness. How Reagan manages this presumably will be examined in subsequent annual White Papers on the workings of the presidency, of which this is the first.