POLLS taken between 1983 and 1986 showed the Republicans making substantial gains against the Democrats. Over this span the GOP pulled even with its rival for the first time since the depression. Analysts wondered, however, whether the gains would last - fueling a long-term realignment - or vanish as the Reagan glow faded. Now in the wake of the Iran-contra affair, we have the answer. In the summer and early fall of 1986, Reagan's popular standing was the highest of his presidency and, indeed, at modern record levels. In October 1986, Gallup found 63 percent of the public approving Mr. Reagan's handling of ``his job as president,'' and only 29 percent disapproving; the CBS/New York Times poll put approval at 67 percent, disapproval at 25 percent - unprecedented for a president so far into his term of office.
The Republican Party at large basked in this bright glow - and stood in virtual parity with the Democrats. Gallup put Democratic identifiers at 39 percent of the electorate, Republicans at 33 percent. According to the CBS/Times poll, the Democratic edge was just 3 percentage points. A September 1986 ABC News/Washington Post survey gave the Republicans a margin of 2 points, while an October survey by NBC News and the Wall Street Journal had the GOP up by 5 points. In 1980, the Republicans had trailed the Democrats by about 20 points.
The Iran-contra revelations sent Reagan's popularity plummeting; according to most polls his approval ratings bottomed out in February and March 1987, 20 to 25 points below their lofty peaks of six months earlier. GOP strategists plainly feared that this dizzying descent and all the buffeting it represented would cost the party its hard-earned gains.
These Republican fears (and Democratic hopes) are not being realized. The GOP's position in party identification did erode in the short run, but only slightly. And as the Iran-contra storm subsided and Reagan's standing with the public partly recovered - rising by late summer and fall an average of 10 points above its February low - most of the modest short-term losses have dissipated. Republicans and Democrats are now at essential parity. For example, September surveys by Gallup and by ABC News and the Washington Post gave the Democrats small margins of 3 and 7 percentage points, respectively, while the NBC News/Wall Street Journal poll had the parties dead even.
The party preferences of young people provide an even more striking measure of GOP gains. From the 1930s through the 1960s, the Democrats beat the GOP in the battle for the loyalties of succeeding generations of new voters. The picture of young people as markedly more Democratic than Republican, and much more Democratic than the elderly, became a firmly fixed part of our understanding of American politics. That situation changed in the 1970s, however. According to Gallup data, a plurality of those who reached voting age between 1974 and 1977, in 1985 identified as Republicans, and each succeeding wave of new voters has given the GOP the edge. Today, people 18 to 24 years old are the Republicans' best group while those who entered the electorate during the 1930s - now in their 60s and 70s - are the Democrats' strongest backers.
Moreover, by 1985, large pluralities of teen-agers - future voters - were giving the GOP the nod.
The Republican revival is proving, then, to be both substantial and durable. A decade of gains has lifted the party up from its post-Watergate nadir and made it the rough equal of the Democrats in overall support. While they have appeared more impressive when the President's popularity was waxing than when it was waning, the Republican gains have persisted through the ups and downs of the Reagan years.
That for a decade the GOP has attracted more new voters to its standard than the Democrats have to theirs, and that the age group about to enter the electorate shows clear Republican leanings, suggest strongly that the present realignment is not yet exhausted.
Thus far, though, the realignment doesn't look at all like what we had expected. It is very gradual, and it accrues from no single galvanizing event such as the depression. It has not to date produced a new majority party, but rather a situation where no one has a majority. And the expression of the present balance is without precedent in American history. The Republicans' and Democrats' bases are not now geographically defined nearly so much as they are institutionally located, in the presidency and Congress, respectively.
As Campaign '88 proceeds, both parties are struggling to understand the implications of these curious partisan shifts - for their electoral prospects and their capacity to govern the country.
Everett Carll Ladd is executive director of the Roper Center for Public Opinion Research and professor of political science at the University of Connecticut.