When I started researching my book, Classified: The Untold Story of Racial Classification in America, the law review literature asserted that racial classification, in practice, was almost entirely a matter of self-identification. While federal law specified the classifications and their definitions, in practice people could check whatever box they wanted, and no one ever checked. In fact, according to the relevant literature, there was only one case, ever, in which an individual's self-identification was questioned. This was an infamous case involving two Irish-American firefighters in Boston who claimed to be African American to take advantage of the fire department's affirmative action policies.
I was confident that there were more such cases, in part because Eugene Volokh once blogged about such a case involving whether New York State could constitutionally decide that a contractor of Spanish descent was not Hispanic for state purposes, even though he was Hispanic for federal purposes. In the end, I found a couple of dozen such cases, mostly involving minority business enterprise preferences, and mostly involving the Hispanic classification, though also others involving claims of American Indian, African American, and Asian American identity. Many of those cases wound up being cited in Justice Gorsuch's concurring opinion in SFSA v. Harvard.
I assumed that these were just the tip of the iceberg, as I relied on publicly available judicial or administrative rulings, or media coverage. Most disputes, I figured, were decided within the bowels of government bureaucracies, and the only way to find them would be to comb through thousands of unpublished records, if you could first figure out where those records were located. It wasn't sufficiently important to my book to undertake such an efforts.
