But this all stems from a claim that there is a bigger culture among young black men to have long hair, for cultural reasoning, than for young white men.

The ACLU report goes into detail about this starting at page 21. Pages 21 to 29 cover racial discrimination.

https://www.aclutx.org/sites/default/files/dresscodereport_2-1-24.pdf

RACE DISCRIMINATION Race discrimination is one of the most common and harmful types of discrimination. Racist stereotypes are deeply embedded in our society, and dress codes are no exception. Because many dress and grooming policies are written based on Euro-centric standards of dress and beauty, dress codes have historically marginalized, discounted, and suppressed styles of dress, hair, and grooming associated with Black people and other people of color. For example, some dress codes prohibit hair styles and textures—like Afros, braids, and locs—that are historically associated with African American hair practices. Others prohibit clothes and accessories—like du-rags, hair beads, and picks—based on associations with race and racial stereotypes, particularly those associated with Black people. Rules like these are rooted in racist standards of professionalism and respectability, and they marginalize many students of color.

But if that is the metric used to label a rule/law as racist, then virtually ever rule and law is racist

Yes, systemic racism exists in our society. It is deeply embedded in our intuitions.

Then why talk about heritage at all?

Because it is relevant to the discussion. The wigs specifically are not.

And who is talking about wigs? Not me.

Depends on the culture. Also you’re talking about modern western culture. Not white culture in general. Even the US, which is a baby of a country, has had presidents who had long hair while in office. Almost as late as the 1850s.

The long hair styles were wigs.

Blatant projection.

An argument about wigs being the cultural of heritage of White men in the United States is disingenuous.

You’re trying to have your cake and eat it too. You want to claim heritage when it comes to black people, but then only talk about modern western culture (which you attribute solely to white people) when it comes to white people. The reality is that if we look at modern western culture, even for black people, it’s predominately short hair. If we want to look at heritage of people, there are plenty of white heritages, include in the US itself, of men having long hair. It’s you who has the double-standard. .

This is argument is historically inaccurate. White men in the US have historically had short hair. It’s been that way since the early 19th century. Black men have a historical culture heritage of long hair that predates the policing of black hair in the United States.

If this is the metric by which we measure racism, then it’s you who is racist

Ad hominem attacks reduce your argument’s credibility. edit: typo