'Given the progress that the United States has made toward remediating illegal discrimination in K–12 education, it may prove difficult for a voluntary desegregation plan today to establish the factual predicates needed to survive strict scrutiny,' the opinion states.'Given the progress that the United States has made toward remediating illegal discrimination in K–12 education, it may prove difficult for a voluntary desegregation plan today to establish the factual predicates needed to survive strict scrutiny,' the opinion states.