> Would it fair to say that racism has really largely been about classism?
Please do some reading on the subject. Cursory reading on the history of labor unions, immigration in America, or literally any book on the US south that isn't Lost Cause mythology will tell you resoundingly yes.
I am not even talking about Marxist authors or Howard Zinn. You can easily find primary sources, the people who historically weaponized racism, telling you exactly how and to what end they are weaponizing their racism.
https://www.thenation.com/article/archive/exclusive-lee-atwa...
Secondly, capitalism is great at co-opting all sorts of messaging. Since you are on HN I assume you are familiar with the concept of a Paperclip Maximizer. The "machine" in this sense does not love you or hate you. You are a customer and they will adopt the aesthetics of your ideology to sell to you, inherent contradictions be damned.
Every oil company that spent the last 50 years denying climate change now pours their money into showcasing their green energy products. Companies who benefit from convict labor of African Americans adopt BLM banners on their websites. Companies who donate to the political campaigns of every republican in both houses of legislature change their logos to pride flags in June.
I dont want to assume but your phrasing makes me think (unless I am misreading it) that you think blm and "wokeness" are elite belief systems manufactured by "the machine", and that more reactionary "working class" ideology (a la Tucker Carlson) is grassroots. I really implore you to consider the Paperclip Maximizer idea and realize that the ideologies you are presented with on TV and print are the ones that have been passed through a corporate filter and sanitized to pose no threat to the machine. What you are seeing is a facsimile of what was once probably a more nuanced belief system.
When was the last time you heard Georgism or Anarcho-syndicalism or de-growth discussed by any talking heads? The answer is never because these concepts are inherently antithetical to capitalism and cannot be co-opted.