I believe there is only one race – the human race. Distinctions between people that use the word “race” are really about something else. I think there are three main ways that people use the word “race” and consequently may act in discriminatory ways toward people they believe are of other races.
(1) Racism of ancestry. This is the oldest kind of racism. It is a racism of “blood”. The one-drop rule says that “one drop” of blood from (sub-Sahara) Africa makes a person a member of the Negro or black race. The appearance of the person does not matter. Their culture or mannerisms do not matter. Only their ancestry matters.
This is the purest racism, which is built on feelings and ideas about racial purity, inherited character, and immutable destiny. There is nothing a person of a deprecated race can do to earn the respect or approval of someone who has this kind of racism.
(2) Racism of appearance. This is an old-fashioned kind of racism. It is a racism of appearance, particularly skin color. If a person appears to have physical characteristics typical of a race, they are identified with that race. Some people who would be classed by their ancestry as one race may be classed by appearance racism as a different race.
This is a mixed kind of racism because people may disagree about who is a member of which race based on their appearance. Lighter skin, straightened hair, and the like may make an ancestrally Negro person seem Caucasian. A dark tan, hair with tight curls, and the like may make an ancestrally Caucasian person seem Negro.
In this case there is little that a person of a deprecated race can do to pass as someone of another race. And what they can do may involve suppressing their natural appearance or personal preferences.
(3) Racism of culture. This is a racism that identifies a person’s race by their culture, that is, their speech, their mannerisms, their clothing and hairstyle, their taste in entertainment, and so on. Someone who does not have the ancestry or appearance associated with a race may still be identified with that race based on their culture. Or oppositely, one who does have the ancestry or appearance associated with a race may not be identified with that race based on their culture.
This kind of racism overlaps considerably with socioeconomic class and education. It is racism because it associates people with races, even though the criteria are culturally defined. A person of one race who changes their speech, their mannerisms, etc. to that of another race may be accepted by persons of another race as one of them.
I think the racism of ancestry is rare today, though the alt-right is trying to bring it back. People are willing to recognize mixed races rather than automatically identify them by the less-favorable race. I think the racism of appearance is declining today. It is still there, especially among the older generation, but is on the way out. I think the most common type of racism today is the racism of culture. While it’s still a form of racism, it has to do with things that could be changed if people wanted to.
That brings up the matter of assimilation and integration. In the second half of the 20th century, assimilation was viewed positively, and there was a push for integration. No more. Assimilation is viewed negatively, and integration is not seen as a social goal. Instead, equality is promoted. Everyone is to be respected and accepted in the place and condition where they are.
I still think that there is only one race, the human race, and the best way forward is to reject all racial distinctions. But this is a minority view today.