As one who grew up in the smug bosom of Midwestern Republicanism, I was pleasantly surprised by the 1980 version. Something nice has happened to the Republican Party.

Or maybe it is only me. Perhaps I am old enough, at last, to enjoy Republicans. Faith of my father, of his father and so on. For years I approached the GOP with an apostate's sour memories. The Republican Party in which I grew up was full of righteous scorn for anyone not discriminating enough to be Republican. In olden days, this meant Catholics, Jews, blacks, members of labor unions, pinko professors, anyone of weird appearance or unorthodox ideas. Life, I discovered later, was more interesting than Republican orthodoxy had led me to believe.

As I say, maybe I left that baggage behind before I came to Detroit. I think, more likely it is the Republicans who have changed.

They seem nicer. More interesting. Less scolding. As devoted as ever, but not so abrasive about it. Except for a sprinkling of nut-bag conspiracy theorists, this convention was notable for the absence of exclusionary hatred. The haters stayed home or have dropped out or overcome their old narrowness.

The Republican delegates told themselves -- and any jaded journalist who inquired -- that those days are gone. The speeches and platform carried the same theme. Their arms are open.

Come one, come all. Come into the Republican tent and hear the handsome cowboy talk about Freedom and Prosperity. Come see the vision of America, the beautiful and bountiful, restored. Feel good again.

This is a very compelling message and one that used to be loosely owned by the Democratic Party, whose leader is now cast as the national scold. Before we examine the fine print of the program and the candidate, any reasonable critic ought to give Ronald Reagan this much: He has stage-managed a rather important transformation of the Republican soul.

The Republican Party may still remain a minority club, may even continue to decline in numbers and someday expire. But Reagan has given them one season of self-confidence and generous feelings. That's an important political accomplishment, win or lose, for them and for all of us.

Despite my preexisting assumptions, I sort of liked the GOP delegates. I liked the furniture dealer from Utah who told me, with the patience of a good teacher stuck with a slow pupil, that Reagan's strong "constitutional bias" is the last hope for the nation. And the county official from the South who isn't sure that Reagan can turn things around in Washington but, by golly, we ought to try. Or the Nebraska farm wife who was perfectly willing to discuss the big issues but equally pleased to talk about her three children. Or the auto parts dealer from Missouri who sees himself and his party arm-in-arm with blue-collar workers -- little guys against big guys.

What I liked about them was the sweet earnestness of their beliefs They do see themselves as squad leaders in a kind of moral crusade to transform the country. They are so sure of victory that the zeal is not overbearing. Why shout and scream when the future is secure? That's fundamental human optimism and, as a longstanding knee-jerk optimist myself, I identify with it.

But the future, is going to disappoint these earnest folks, I think. That is not a political prediction about the November election but a statement about deeper historical dynamics -- forces which are stronger than the cowboy and not recognized by his followers. These people will feel terrible, of course, if Reagan loses in November. But if Reagan wins and becomes president, I think the future is going to break their hearts.

When we get beyond the attractiveness of open-armed optimism, the new Republicanism does not look so coherent or plausible. I am not questioning the sincerity of faith, only whether it is germane to the 1980s, whether it makes sense against the reailties that any president must confront.

The Reagan credo, as expressed in the GOP platform and his own acceptance speech, artfully marries contradictory ideas. The fundamental premise is that nearly every affliction and grievance, social or economic, will be better dealt with if power and money are taken away from the federal government in Washington and given to other parties -- private citizens, private corporations, state and local governments, churches and other non-federal institutions.

At the same time, while the Republicans blame the government for all the stress signals in family life, they implicitly want more social control by government in order to defend "the traditional American family" against change. This leap of logic requires one to believe that somehow the feds are to blame for divorce or homosexuality, for working mothers or those young couples "living in sin," as we used to call it. The distress over family life is real enough, but the Republican response does not plausibly address the realities.

One man's decay is another's liberation. The earnest crusaders seem unable or unwilling to accept that conflict or even see it. Amid all the talk about morality and traditional families, I was struck by the fact that the GOP entertainment planners selected Glenn Campbell and Tanya Tucker to sing the national anthem. Glenn is living with Tanya; he left his wife Sarah, whom he stole from his old friend, Mac Davis. I read all about it in People magazine recently. Republicans may be open these days to racial minorities and blue-collar workers, but they still have trouble with sex.

More fundamentally, if one reads through the Republican platform, there is one persistent theme, whether the planks cover farm prices or urban revitalization or fighting inflation or whatever: Nobody gets hurt. The GOP makes a point of this, another line stolen from the Democrats and crucial to the Republican sense of optimism. It's also the Republican version of the free lunch.

The idea that everyone-will-be-taken-care-of is much more plausible when connected to the liveral welfare state. It seems to undermine the Reagan credo, which says in effect that everyone should be free to take care of themselves. A political party cannot have it both ways.

Nor a president. Ronald Reagan in the White House would most certainly be confeonted by this fundamental contradiction. It was good politics in 1980 to make the promise -- nobody gets hurt -- but if Reagan were to begin dismantling and dispersing the federal government, its authority and resources, we would see the injured forming lines outside his door.

How should he respond? How can he? Every choice Reagan makes will define the class interests concelaed beneath the broad philosphy -- somebody wins, somebody else loses. As this happens, the identified clientele of the new Republican Party may not look so different from the old Republican Party. You cannot open your arms to the downtrodden while giving the cash to the wealthy.

Or Reagan could try to finesse the hard choices, as previous White House tenants usually have done. Richard Nixon crudely abandoned his own promise to reduce federal powers and creeated an extraordinary new system of federal controls. Jimmy Carter promised less bureacracy and ended up creating much more. While Reagan preaches the "little guy" faith in free enterprise, the "big guys" from Detroit and Pittsburgh and Wall Street are in the nation's capital demanding greater federal protection and subsidy for basic American industries. I do not think Ronald Reagan is equipped to overturn those forces; they are too deeply enmeshed in the changing nature of the world.America is no longer an island.

That's why I think the conversative faith is in danger of colliding with the cruelest fate -- the disillusionment of a dream fulfilled. As outsiders for so long, the Reagan conservatives have been able to look forward to a perfectible future when their ideals would prevail, when their trustged leader would at last be in the saddle. But if the cowboy wins, they will no longer have the dream. I believe they will discover that life is more complicated than their new Republican orthodoxy leads them to believe.