A new wave of black activism is sweeping through South Africa, upstaging what was meant to be a whites-only debate over the future of this country. Whites go to the polls Wednesday to vote on a proposed new constitution after weeks of protracted discussion over whether the measure represents real ''reform'' - as the government contends - or not.
The new constitution would open up the all-white Parliament to Coloreds (persons of mixed race descent) and Indians. But the black majority would remain excluded and relegated politically to 10 tribal ''homelands'' - most of them far away from job opportunities.
Weighty as the referendum is, analysts here are particularly struck by what is happening among blacks, who are meant to have no part in the present debate.
The constitution has sparked black resistance on a scale not seen in South Africa since the mid-1970s, when protest led to riots in Soweto and other townships, say close observers of black politics.
It is premature to say a new chapter of black protest is unfolding. The will to stage major protests may be there among blacks, but deep ideological divisions in the black community remain.
Also a crucial factor in any plans for protest: The state is already on the move against budding black political organizations and could stop them dead in their tracks by banning the groups outright.
But analysts see two lessons emerging from the new surge of black activism:
1. Its rapid escalation suggests there is a high degree of below-the-surface discontent among blacks just waiting to be tapped.
2. There remains a dynamic internal dimension to the black struggle that is often lost sight of as attention is focused on a rising sabotage campaign being waged from outside South Africa.
The present wave of black activism differs from the 1970s' wave in one important respect, observers say. That is, it has a broader base on which to build.
The most significant development since the government squashed most black political activity in 1977 has been the emergence of a black trade union movement. Some of these unions have eagerly embraced political issues. But major union bodies like the Federation of South African Trade Unions have stuck more closely to worker issues.
Still, black workers have a new lever of power that could make any future upheaval on the scale of Soweto (which erupted in riots in the mid-1970s) a more serious crisis for the state. And the government's concessions to blacks in the labor field cannot be easily reversed since they were enacted in the first place out of necessity for the overall well-being of the South African economy.
Also, while the post-Soweto period has been marked by a surface calm, scores of localized black groups have taken root. They are organized around issues like rents, bus fares, housing, and education.
Indeed, the main aim of black protest in 1983 appears to be to forge a unity between these splintered black political groups. Although a monolithic black movement is clearly not in the cards, some consolidation is taking place.
The tactics and objectives of today's black protest, to the extent they can be discerned, are pragmatic and down to earth. Strong emphasis is being placed on organization, in hopes of withstanding state repression. And there is a focus on clear-cut issues rather than preoccupation with ''talk of a future South Africa,'' as one activist puts it.
Hardened by years of harsh government treatment, black activists today have no illusion about easy victories. They themselves counsel caution about expecting too much from current political initiatives.
''Those passing judgment on us already are making a mistake,'' says Patrick Lekota, national publicity secretary of the newly formed United Democratic Front. ''It (the UDF) is a new initiative and all we are confident of is that our strength will grow.''
The UDF burst onto the scene in August with an inaugural mass rally in Cape Town that literally found supporters hanging from the rafters to gain a view of the proceedings. Claiming to represent more than 500 organizations, the UDF is the broadest-based antigovernment initiative South Africa has seen for years.
But the UDF is not so sudden an achievement as it might appear. Its roots go deep. It is essentially a superstructure laid over existing anti-apartheid groups that have been gaining strength since the 1977 state crackdown.
The UDF represents the strongest of two traditions that now divide the ''radical'' end of the black political spectrum. The UDF's roots tie in with the tradition of the African National Congress (ANC), the banned guerrilla group now waging a sabotage campaign against South Africa.
In short, the UDF sees itself as a mass, multiracial alliance working to dismantle apartheid. This would make it similar to the so-called Congress Alliance formed in the mid-1950s between the ANC and other protest groups, including those representing whites.
The other tradition gaining some new ground is that of ''black consciousness, '' a philosophy of black self-assertiveness that excludes cooperation with whites. Black consciousness was most forcefully articulated by Steve Biko, who died while in police custody in 1977.
Black activists aligned with the tradition of the ANC and those following in the footsteps of black consciousness are sharply at odds. But the constitution seems to have galvanized each camp into trying to consolidate its ranks.
The Azanian People's Organization (AZAPO), the main black consciousness group , sees the proposed constitution as a direct threat to its own philosophy. Adherents of black consciousness view their ''black'' constituency as all ''nonwhites.'' The government's plan to co-opt Indians and Coloreds into collaboration with whites cuts directly across the ''black consciousness'' constituency.
The UDF sees the constitution as a paramount apartheid initiative, aimed at irrevocably dividing whites from blacks and making more difficult the UDF's ultimate goal of a ''united democratic'' South Africa.
The constitution issue also is galvanizing moderate blacks like Zulu Chief Gatsha Buthelezi and some other homeland leaders. The gulf between these leaders and the more radical urban-based activists is huge, but the constitution is giving them opportunity for agreement.
Buthelezi has warned in the strongest terms that his brand of moderate politics will lose credibility should the constitution be implemented. And five other homeland leaders, including Chief George Matanzima of Transkei, which was the first homeland to accept Pretoria-style ''independence,'' have joined Buthelezi in rejecting the constitution. They have pledged themselves to a ''united'' South Africa and a national convention to hammer out a constitution acceptable to all.
The UDF has clearly captured the initiative in internal black politics, but its own leadership is not certain of its longevity. The UDF was formed explicitly to oppose the new constitution, and the so-called Koornhof bills aimed at granting more local government power to urban blacks while tightening the influx laws.
''The UDF is an alliance of first-level organizations,'' explains Mr. Lekota. ''Today the groups are cooperating to oppose the constitution. Whether tomorrow they will continue to cooperate will depend on their own assessments.''
Right now UDF officials are working black townships on a house-to-house campaign to ''educate'' people about the implications of the proposed constitution. And the UDF is already gearing up to discourage participation in local black elections slated for late November.
The way Lekota sees it, the UDF has been built from the ground up and that is its strength.
Although the UDF eagerly embraces the tradition of the ANC, it is careful not to suggest it is a modern-day substitute for the ANC. ''We don't purport to substitute for the accredited liberation movements of the people,'' Lekota says.
Activists with firm ANC links, like Winnie Mandela, are strongly behind the UDF. Albertina Sisulu, wife of imprisoned ANC official Walter Sisulu, is UDF president in the Transvaal Province.
The one thing the current crop of black activists have in common is skepticism about how long state tolerance will last. Earlier this year some banning orders were lifted, and some blacks serving jail terms for political activities were released and allowed back into politics.
Much of this tolerance stems from the state's campaign to convince its white supporters that it is sincere about reform. But the tolerance is already unraveling. Some UDF and AZAPO meetings were banned recently, and their officials harassed.
''We haven't done anything to justify their bannings,'' says Lekota.
Lekota himself was recently detained for two hours by security police. He said they warned him he would be back in jail if he didn't stay away from the UDF.
The experience reinforced his concern that official tolerance of black opposition may soon be ripped away. ''I'm afraid it is just an Indian summer for us,'' he said.