It's worthwhile being technical here. "Affirmative action" is not sufficiently specific. You are speculating about whether the Court might hold that race-conscious admission programs at public universities deny equal protection to white applicants. Such race-conscious admissions programs are remedies for past constitutional violations, designed to prevent future racial discrimination. Defending them on the generalized ground that "diversity is good" turns out to be a poor choice. The argument that the State has a compelling interest in fostering "diversity" sufficient to justify race-conscious admission policies that prefer people of African or Mexican descent to supposedly "more qualified" white people is rejected by many .... white people.

But the State does have a compelling interest in preventing unconstitutional racial discrimination. That persons of Mexican and African ancestry would be discriminated against in all aspects of life in Texas, including higher education, if federal force were no longer applied through the courts, is pretty much apparent to everyone in the world except Tejanos.

What you do not say in this essay's predictive effort to look past a possible decision of the Supreme Court, is that a ruling shortening Justice O'Connor's twenty-five years to ten would result in a heightened interest in making class rather than race the basis for admissions preferences. The cynical effort to use "race neutrality" as a barrier to anti-discrimination reform has depended on the "strict scrutiny" supposedly required to review the equal protection effect of remedial measures design to prevent discrimination. But class-based or poverty-based classification is not subject to heightened scrutiny under equal protection dogma, because capitalism needs to consider it merely "rational" to oppress the poor. So "reverse discrimination" on behalf of the poor is not hard for the State to justify against assaults from reactionary pseudo-equality theory.

Nor do you consider the effect of doctrine such as that you imagine the Court making on its own long-term position in a society that will not be run by a white majority in the next generation. The Republican Party as a whole, not only its Supreme Court justices, are risking their fate if they do not come out of Richard Nixon's white-resentment "Southern Strategy," well as it has worked for them over the last generation, in time to avoid becoming anathema to majority-minority America. John Roberts can see that, I suspect, as clearly as he could see the long-term disadvantages, for him and the Court, in the destruction of the ACA.

So this is a good start, but a little more pressing will take you a good deal farther towards your intended destination.