The example you provide is highly relevant.
Mzungu for years supported the Apartheid regime as it violated civil rights and presided over a minority dictatorship based on race.
The publicly stated reason for this inhuman position was that SA was fighting communism in Mozambique and Angola.
By the time Mandela was President of South Africa, he was still listed as a "terrorist" and not eligible for a visa to the US. He had to get a special dispensation to enter for the first time.
The denial of the Visa has not stopped Rachel Ruto from smearing the whole country with Elianto Oil.