HOUSTON. — THE IMPASSE in South Africa continues, as the Xhosa-dominated African National Congress stalls for the time it needs to settle its own leadership problems, convert itself from VTC an exiled paramilitary command structure to a functioning internal political party, and consolidate sufficient black support to fend off Zulu domination of the negotiating process.
It must also draft its own outline of a post-apartheid South Africa, a task it must postpone until it has completed its own reorganization. Until it has such an outline, it can hardly negotiate anything. The ''Freedom Charter'' (which to date has served as its only political declaration) cannot serve as a negotiating base; it is long on generalities and noble rhetoric, and short on specifics -- and still calls for a Marxist-oriented socialized economic structure.
President F.W. de Klerk, on the other hand, has carried the dismantling of petty apartheid about as far as he can under the current structure, and does have in hand a cohesive draft of a constitution which will serve as a basis for negotiations.
While neither the United States Constitution nor the British Westminster structure can be applied directly, Mr. de Klerk's draft roughly follows the American model -- modified for South Africa's demographic divisions. It incorporates a universal franchise and a Bill of Rights protecting not only individual human rights but the languages, religions and cultures of all ethnicities. The ANC has no quarrel with these provisions.
The crux of the change calls for drastically decentralizing the current structure and passing power to 10 semi-autonomous provinces with full control of internal affairs, and with further powers passed on to local councils. These proposed provinces just happen to correspond to an elaborate ''regional economic development'' scheme South Africa prudently devised and staffed several years ago, so that a goodly proportion of the administrative infrastructure is already in hand. Economically and demographically, they are far more sensible than the current hodge-podge of four provinces and 10 ''homelands;'' since the ANC is not opposed to the devolution of power, and accepts community rights for language and education, the proposed geographic framework should prove acceptable.
Chief of state would be a largely ceremonial post, with a prime minister -- chosen in rotation from each province -- wielding political power. A 300-seat lower house would be elected by universal franchise and proportional representation; a 200-seat upper house half by the provinces and half by political parties on a proportional basis (following the complex but eminently workable German model). The ANC is likely to demand unitary elections for the legislative branch rather than adopting such a federal system; the Zulus -- fearing Xhosa control -- will unquestionably opt for the regional basis.
Constitutional amendments would require a two-thirds majority -- lulling both white and Zulu fears of Xhosa control; an independent high court would safeguard the Bill of Rights and settle disputes between provincial and central government.
The economic structure would continue as a free-market, private-ownership system; the Zulus (and other black ethnicities) are in hearty agreement, but the ANC -- still clutching the Marxist ''Freedom Charter'' -- may balk. White hypersensitivity to threats of nationalization go far beyond a desire to ''retain privilege;'' the preservation of the economy is critical to all, and socialistic blundering by incompetent ideologues would inevitably bring it crashing down.
The new framework would result in five rural, predominantly black provinces, three (the Western Cape, the Orange Free State and the Eastern Transvaal) with white urban majorities, and the remaining two mixed (but in regions, such as Natal, with relatively lower black-white tensions). The lower house would be overwhelmingly black, as would most of the civil service. The cabinet would follow the Swiss model, with seven members elected by the lower house, one from each province, and one from each political party. This would facilitate coalitions and shifting alliances, rather than the permanent head-on confrontation inevitable in both the British and American systems.
Mr. De Klerk hopes to implement the new provisions piecemeal, as agreement is reached (giving all hands the opportunity to enter the water gradually); the ANC is still thinking in terms of an overnight, Big Bang change. An enormous amount of selling lies ahead; by Mr. de Klerk to the white communities as well as to the ANC and the other black ethnicities, and by the ANC leadership (if it finally buys the package) to its radical adherents.
There is no guarantee such proposals will be accepted by all, let alone work if they are. They do indeed provide political freedom, and a lion's share of power for the blacks. They will not better the material lot of the millions still mired in poverty, hunger and dirt -- but no political changes could bring that about. They can only, with freedom and liberty, offer hope for the future.
Mr. Morris is the author of ''The Washing of the Spears,'' a history of the Zulu nation.