The way the cookie crumbles. Start with the charts (i.e., the ‘60s population) then how FR voted.
Pretty amazing to me as well. But still I think the charts were reasonable.
It's probably regional. Growing up around DC, white kids were exposed to more black music, Motown, rhythm & blues, etc. than other parts of the country, and it did more for Civil Rights among the young than marches and protests. We also had gatherings of choirs from churches all around DC-Baltimore for the annual Methodist Hymn Sing in Constitution Hall in DC, which exposed the white suburban kids to the glories of black gospel singing. And, in high school in the late 50s-early 60s, white kids could go to some black-owned clubs in DC, even during a time of considerable racial tension. Even the intimate Bohemian Caverns, owned by hipster African-Americans, that graciously tolerated white kids coming in to hear great jazz. It was dark and smokey inside with dark walls, and the ceiling was like being in a cave, decorated with long plaster stalactites embedded with glittering mica dust.