UPDATE: In chapter 10.3.2, Sociocultural Designations, the examples of capitalizing racial categories were updated to reflect the decision to capitalize Black and White and to use them as modifiers, not as nouns. This change was made August 27, 2020.
Capitalize names of languages, nationalities, racial categories, ethnicities, political parties, religions, and religious denominations. Do not capitalize political doctrines (conservative, progressive) or general forms of government (democracy, monarchy). Capitalize ...