Chief Gatsha Buthelezi is the controversial Zulu chief and leader of the still legal Inkatha opposition movement to South Africa's apartheid policies. In conflict with both the current Pretoria authorities and black African supporters of violent revolutionary action, Buthelezi is said by his supporters to represent a nonviolent, multiracial and liberal- democratic opposition leadership. His is a middle ground that Buthelezi's critics say is fast eroding under the increasing polarization generated by the policies of the Pretoria regime. Buthelezi's supporters counter that the chief is the most popular black African leader in the country. They cite among other evidence a recently completed four-year study by West Germany's Arnold Bergstrasser Institute, which polled urban blacks in different parts of the country and concluded that Buthelezi is supported by almost half of the urban blacks.