Here the librarians are not defending free speech but take a political position on this issue. For example, they could have put up a book "Book about White Liv

Here the librarians are not defending free speech but take a political position on this issue. For example, they could have put up a book "Book about White Lives - The European Experience". This wouldn't go over well in the current political climate, I assume. So since the police officers are on the other side of this issue, it makes sense that they wouldn't want to be implicitly defending the opposite side.