As Ronald Reagan marches toward a decisive victory Tuesday, a central question emerges: is a realignment of the electorate taking place? This question, however, may miss the point altogether. Instead of a realignment of the partisan allegiance of the voters, the central change may be in the economic contours of the "natural" majority. If so, the present alteration of the electorate is fundamentally nonpartisan, although it is clearly to the benefit of the Republican Party.

From the 1930s at least until the 1960s, the Democratic Party established a "natural" majority, which became known as the New Deal Coalition. This majority was unquestionably partisan -- its adherents identified with the Democratic Party -- and, in economic terms, it was bottom-heavy. The strongest Democratic margins were to be found at the bottom of the distribution of income and wealth. This majority was shaped, in effect, like a pyramid, narrowest at the top, among those who make the most money and among those with the most extensive holdings.

The "economic shape" of the Democratic majority gave direction and vitality to the content of government for 40 years. The core of political power within the Democratic voting majority was the bottom third of the income distribution, and the result was the enactment of tax policies and social programs modestly redistributive in a downward direction, providing money, food, job training and medical care to those in the middle and bottom of the income distribution.

Since 1952, Democrats have been defeated in five out of eight presidential elections. But the continuing strength of the "natural" Democratic majority was demonstrated by the fact that, until 1980, no Republican president seriously sought to reverse the direction of the "Democratic" content of government. The inability of Republican presidents to reverse Democratic policy reflected the fact that they were elected either on the basis of personal attributes -- such as Eisenhower's reputation as a war hero -- or on the basis of conflict within the Democratic majority -- such as the divisive intraparty struggles over the Vietnam War in 1968 and over the nomination of George McGovern in 1972.

Developments over the past four years suggest, however, that there has been a fundamental change in the political/economic equation. Ronald Reagan was elected in 1980 with a bloc of votes bearing a shape directly inverse to that of the traditional Democratic majority. In effect, Reagan's majority four years ago represented the turning upside-down of the Democratic pyramid, with the broadest part of the pyramid -- that is, the new majority -- at the top of the income distribution, and the tip at the bottom. Reagan's margin of victory increased in direct proportion to the income of the voting bloc, and his tax and budget cuts succeeded in distributing the benefits of government in an upward direction -- to the same group providing his strongest voting margins -- while penalizing those at the bottom, whose votes remained firmly Democratic.

The same, top-heavy pattern of support for Reagan is recurring in the current election. This was strikingly apparent in a September Washington Post-ABC poll. Reagan led Mondale by 15 points overall, but among the poorest voters -- those with incomes below $12,000 -- Mondale ran ahead of Reagan by a 26-point margin. Among the most affluent -- those with incomes above $50,000 -- Reagan had a 40- point margin over Mondale, 69-29.

The income pattern of the Reagan vote is parallel to the income patterns of voters who identify themselves as Republicans, although the Reagan vote is much larger in every income group. If, then, Reagan is in the forefront of a partisan realignment of the voters in favor of the GOP, it is a realignment in which the affluent will be the dominant force. In economic terms, such a partisan realignment would suggest that the upward distribution of government benefits in the first Reagan term has set a precedent for future government policy making. The rich will get richer, and the poor will get less.

There are, however, a number of factors suggesting that the political changes taking place today do not involve a realignment, particularly a partisan realignment with the strength and vitality of the Democrats' New Deal Coalition.

For one, the decline of the "natural" Democratic majority resulted less from a Republican challenge than from a host of other changes in the society at large. From 1960 to 1980, the percentage of the work force holding white-collar jobs rose from 43.4 to 52.2, while the blue- collar percentage fell from 36.6 to 31.7. Over the same period, per-capita income rose in real dollars from $3,069 to $5,322, a 73 percent increase. Union strength, as a percentage of the work force, has been about halved. In the South, race has become the critically important factor in partisan divisions, with the result that in presidential elections, the Democrats are a poor, heavily black party, while the Republicans have emerged as the party of the white middle and upper class.

Perhaps the most damaging development for the Democratic Party was a self-inflicted wound. From 1960 to 1980, Democratic Congresses allowed bracket creep and sharply increasing marginal tax rates (in 1960 a consideration only of the top 10 percent) to become a fact of life for many blue-and white-collar working men and women. A carpenter promoted to foreman with a 50 percent pay hike in 1960 would see no increase in his tax rate, while the same carpenter in 1980 would see his marginal rates go up by at least 6 percent.

All of these forces have worked to undermine the traditional Democratic majority, but there is no evidence that they have produced a significant revival of public identification with the Republican Party; in fact, the evidence is to the contrary. From 1972 to 1984, according to the Committee for the Study of the American Electorate, Democratic registration in states with partisan registration has declined from 43.8 to 35.2 percent, while Republican affiliation has fallen from 24.4 percent to 22.8 percent.

Perhaps more significant, Martin P. Wattenberg, in his book "The Decline of American Political Parties," shows that parties have generally lost meaning to the American electorate. From 1952 to 1980, the percentage of the public with positive views of one party and negative views of the other -- i.e. strong partisans -- has declined from 50.1 percent to 27.3 percent. At the same time, the percentage of the public with neutral or flat feelings about both parties has nearly tripled, from 13 to 36.5 percent.

What these figures suggest is not a Republican realignment but, instead, an extremely fluid electorate, without partisan roots. In a development which may at first seem contradictory, these figures point toward the growing importance of political party structures. In a fluid electorate without strong ties to either the Republicans or Democrats, the ability of the parties to finance, develop and use effectively the mechanical and technological elements of politics -- television, polling, direct mail, the computerization of electoral data -- become critically important to the ablity to influence the voters, not just in political campaigns but also in building support for legislative agendas.

On this score, the Republican Party has flourished. Money is the most obvious area of GOP success, but it is by no means the only area. In the political arena, the GOP has capitalized on its financial advantages to produce waves of generic television advertising encouraging the public to vote Republican; to pay for daily tracking polls in marginal House and Senate races in order to catch minute changes in public opinion; to computerize the demographics and voting histories of precincts across the country; to turn direct mail into a highly targeted system of campaigning. On this front, the GOP has been able to walk all over the Democratic Party. The most recent evidence of this has been in the drive to register voters. On what should have been ideal Democratic terrain, the GOP has held its own, as the Democrats failed to put together a well-organized campaign to mobilize the nonvoting electorate.

The Republican Party and its allies have demonstrated the same savvy in both mobilizing sympathetic constituencies and in building intellectual support for legislative agendas. Such groups as the American Coalition for Traditional Values, which registered white, fundamentalist Christians, and the American Defense Foundation, which has been registering members of the Armed Forces, have been financed in large part by Republican fund-raisers and the Republican Party. Similarly, growing GOP muscle has been intellectually nurtured by the explosive growth of conservative think tanks -- Heritage, American Enterprise Institute, Hoover, and a host of others -- in what amounts to the creation of a new intellectual "establishment" countering the traditional liberal establishment.

The 1984 election may not be a realigning election, but, given the effectiveness of the Republican Party structure and of its allied organizations, and given the parallel weakness of the Democratic Party structure, the short-term results may be identical to those of a national realignment.

In 1985 the federal government is likely to address both the deficit and proposals to alter the tax system, two related issues, each of which has the potential for radically altering the distribution of government benefits and tax burdens. President Reagan appears headed toward victory with an economically top-heavy majority larger than that producing his 1980 mandate. If this majority extends down the ticket into a Republican gain of 20 or more seats in the House and continued GOP control of the Senate, the political pressure will be to reduce the deficit and alter the tax system in ways that do the least harm to the group providing the strongest support -- the affluent -- and to place the strongest burdens on those least likely to vote Republican -- those at the bottom of the income distribution.