Moreover, the category of “white” is deceptive. I suspect that corporate boards have few people of Appalachian descent, and many people of New England Puritan descent. Understanding what causes that disparity would probably reveal structural mechanisms that affect other groups as well.
At bottom, this law suffers from the same defect identified by Judge Thapar in striking down racial preferences for SBA loans: https://www.opn.ca6.uscourts.gov/opinions.pdf/21a0120p-06.pd.... Maybe there is a kernel to this law that passes Constitutional muster because it addresses concrete harms to specific groups that can’t be remediated in a less discriminatory way. But the intersectionality approach of lumping everyone from ADOS to immigrants to LGBT people into one category for favorable treatment isn’t going to fly under civil rights laws.
I personally am in the "class matters more in terms of discriminiation than race", but I acknowledge serious and well-intentioned and well-informed objections to this understanding. I would prefer to see us focus on class-based discrimination (with class defined primarily in economic terms), because I think this more equitable and ultimately gives us greater (social) bang for each (legal) buck. That said, the category of "underrepresented" in the CA law is broadly (though not precisely) in line with current legal understanding, and I'm not sure it's based on a different concept that current civil rights laws or jurisprudence. The real issue is whether the state can pro-actively discriminate in an attempt to remediate the discrimination it has stated as its target.
Moreover, the California law improperly conflates discrimination with structural disadvantage. It’s definition of “underrepresented” reflects people who might face discrimination. But that’s a different thing than facing structural disadvantages—persistent disparities that can’t be remediated simply by addressing prejudices conduct—which is the linchpin of affirmative action programs.
Hispanics and Asians are just modern day Italians or Irish. They may face discrimination, but the data shows that they don’t really face structural barriers to closing gaps with “white” Americans. Appalachians, by contrast, likely don’t face much discrimination, but face large and persistent structural gaps. These are two quite different categories and it’s nonsensical to conflate them.
No such thing as a protected group ... sure, but there are characteristics that is legal to discriminate on the basis of (e.g. you like King Crimson too much) and ones that are illegal (e.g. you have a Y chromosome)
CA's definition of "underrepresented" does not reflect who might face discrimination; it reflects people who are underrepresented in certain kinds of positions in society and are prima facie concluded to therefore be discriminated against.