the overall framing of the racial struggle in the book is presented such that it transcends the class struggle and indeed surpasses it as the fundamental stratum of oppression.
No, that's not the "overall framing" and if it was you would be able to substantiate your arguments with quotes from the source.
The situation is different to that in Europe because USA is a settler colony. Sakai is Marxist and uses Marxist analysis in his history of class in the USA.
It says "mythology of the white proletariat" - i.e. we've been lied to about the history of white workers in USA. You can't seem to find more any evidence for your assertion besides the title of the book - I assume that's where you stopped reading.
Yes, that seems pretty inaccurate to me. To show that it is accurate you need to find quotes to support your assertion. This is not being 'obtuse' - this is the basics of making a properly Marxist analysis.
He says its "socially constructed" right there! I can't see anywhere where he says race "will always have a 1:1 relationship with class" like you claimed. Saying that he leaves it up to the reader to "connect the dots" - more accurately he doesn't say it at all. Probably best not to make things up if you can't find quotations to support your assertion.
I'm saying that it's not really an interpretation at all since it doesn't quote his works or really discuss them.
he says that race in the US will always have a 1:1 relationship with class
Where does he say this? Using quotations please.
This has zero quotes from Sakai.
How is Sakai "anti-marxist"? Using quotes, please.
Do the Bruenigs even count as leftists? They seem to be liberal welfare-state Catholic weirdos.