I wonder if that is part of it. As the country has gotten less white, we hear (or maybe care) more about bias-induced injustice, and it’s harder for the declining majority to be complacent when “blame the Black guy” gets a court to give you what you want. Local, elected judges have always been a partisan nightmare, but I feel like it’s really the last 10 years, since they eliminated the filibuster for federal judges, and especially since 2017 for SCOTUS, that national courts have lost credibility.