He never said "primarily".
"He also referenced James Baldwin and Walt Whitman, who are two of the most famous gay writers in American history."
He was making the point that Obama had deliberately tried to tie black rights to LGBTQ+ rights and in he referenced a black woman and 2 famous homosexual men, one of whom was also black.
You can watch his talk, which was summarized in that article here:
https://youtu.be/bySvwoJQkcQ?t=113
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On a separate note, Obama is making the argument that people have made mistakes in the past on banning books, and therefore libraries should not ban these books, including graphic sexual books available to & in some schools even required reading for children, some of whom are quite young.
Do you believe, as he seems to be making the case for, that no library should ever ban any books? For anyone? All books should be available to everyone?
Do you think that it should be reasonable that libraries should perhaps do some vetting regarding books that might go against societal standards in their community? Or that might potentially cause harm to people, or that might not be appropriate for children?
Should parents not have a right to express their opinions about what their schools and libraries should be giving to their children?