Have Canadian prime ministers from P.E. Trudeau forward been mainly French-Canadians or Anglo-Quebeckers because of the whole bilingual/bicultural thing and what not, while white South African prime ministers and presidents (until 1994, of course) were all Afrikaners because of first (1910-1948) the post-Boer War Afrikaner-Anglo compromises and then (1948-1994) apartheid-era Afrikaner National Party rule?
I am not sure these two things are that comparable. One of the reasons that many prime ministers came from Quebec is simply because winning Quebec has been a very important part of winning elections. However, Ontario also has that distinction (and indeed, winning these two provinces essentially guarantees you a majority in Canadian politics) and an equal number of Prime Ministers have come from Ontario. On the other hand, in South Africa, Afrkikaners have been a majority of whites since the start of the Cape colony, and even before the Boer Wars retained a great deal of power and influence in British South Africa.
/r/Afrikaans