For Ronald Reagan this fall, the presidential race pits him against more than President Carter and the Democrats. In some respects, his most difficult opponents are phantoms arising out of his own party's past.

Reagan must run against the legacy of the Republican right wing and the memories of the disasters that befell Barry Goldwater and Richard Nixon. It is a formidable task, full of political ironies, for the Republican right that has totally captured the GOP in recent years remains Reagan's most ardent bloc of supporters.And ideologically he represents almost the perfect spokesman to emerge from their ranks. At the same time, to win he must convince voters that he stands for something broader.

After nearly a month on the road talking to voters, it's clear that Reagan has not yet succeeded in allaying those doubts, although it's certainly not for lack of trying. Therein lies an even greater irony: Reagan's candidacy offers the best chance for a true political conservative to win the presidency in more than half a century. But one of his biggest problems continues to be the belief that he is too much in the mold of the conservatives that produced Goldwater and Nixon.

One of the more intriguing aspects of this campaign has been the absence of passion among many Republicans. The contrast between their views now and those they held 16 years ago during the Goldwater-Johnson presidential contest is sharp.

In that 1964 race, when the GOP cry was that it was offering the country an ideological conservative choice instead of an echo of liberal Democratic positions, support for Goldwater was vocal and emotional. There was nothing easygoing about it; many of the Goldwater people you met then spoke of their candidate in fervent, zealous tones.

Everything seemed to be viewed in terms of the blackest blacks and grayest grays. Talk of conspiracies and "comsymps" and Marxist-Leninists at work inside Washington filled the air. One Goldwater volunteer then told of how he had taken a two-months' leave from his job to labor until late at night, seven days a week, in a local campaign headquarters office. His wife, who joined him there, explained why they were working so hard by saying urgently: "The people are up in arms. We want our country back."

They were crusaders; they also were convinced they were going to win.

The shock of that crushing defeat lasted long beyond the election. Nixon, in his two victorious presidential races, never stirred the emotions that were so memorable a part of the Goldwater campaign. But Nixon's fall dealt an even greater blow to Republican conservatives. It is one from which they have not entirely recovered.

Now you hear concerns about Reagan from Republicans. They are worried that Reagan has been too identified with narrow interests. To employ the great cliche of this particular campaign, they are fearful Reagan is "perceived" as being too far on the right to attract the kinds of support he must have to be elected on Nov. 4.

Some of their expressed doubts go beyond unease about superficial public impressions of their party's candidate, of course. They do not like the "Moral Majority" types who are so outspoken in their views on such single issues as abortion and who are lined up so solidly behind Reagan. To them, that association recalls the true believers of the Goldwater days.

They are moderates, generally well-educated and well-to-do, and think of themselves as having long since gone beyond voting blindly for a Republican, even though they retain that party affiliation. The loss of such voters was a key to the Goldwater debacle.

I remember one voter in that campaign, who considered herself an Eisenhower Republican, explaining why she couldn't vote for Goldwater: "The things they say turn me against him," she said, referring to the more extreme Goldwater partisans she had encountered.

There is, however, an important difference between the Reagan supporters of today and those who clamored for Goldwater. Some of the most dedicated Reagan followers take pains to point out that Reagan himself is no right-wing radical. They remember the reasons for defeat in the past, and are anxious that Reagan be dissociated from the extremists in their party. And so it seems, from the way he is campaigning, does Reagan.

Reagan and his running mate, George Bush, are not making the ideological mistakes of the Goldwater campaign. By courting blacks blue-collar workers and urban dwellers they are trying to persuade voters they are not out to turn back the clock and undo progress. Bush for instance, is stumping the country, calling the GOP "the new party of hope, the new party of compassion." He goes before city planners and says Democrat-inspired charges that a Reagan administration would cut off aid to the cities and eliminate existing federal unemployment and social welfare programs are "outrageous allegations that are not true." Reagan offers more of the same during his public appearances.

But unfair or not, the old doubts persist. Reagan has not yet been able to exorcise the GOP ghosts.