Calling Kamala's father's side of her family white is a stretch. Her paternal side is clearly mulatto or at least has visible SSA ancestry. I literally have Jamaican family members that look like Kamala's paternal family (As far as I know, I'm not related to them). Also being Jamaican is both a nationality and ethnicity. Nationality as in it's a recognised polity/country.
Ethnicity, when most people think of a Jamaican they picture a person or most people who have visible SSA ancestry and descend from the West and Central African slaves that were sent to Jamaica via the Transatlantic Slave Trade event from the 1500s to 1800s (plus the later West and Central Africans that came after slavery was abolished and mixed into the black population during the 1800s). And rightfully so, as most of Jamaica's population is Black/SSA in terms of autosomal genetics (most Jamaicans are 80%+ genetically Black/SSA).
We Jamaicans formed our own culture on the island, no different than other Afro-descendants of the Americas via the TAST (Haitians, Dominicans, Afro-Brazilians, Afro Columbians, Afro-Guyanese, ADOS/Aframs, etc) thus we are also an ethnic group.
Nevertheless, Kamala is unpopular among many Americans (regardless of colour, ethnicity, etc). I don't blame them.