This is a substantive constitutional event with significant A-score (46.1) driven by rule of law (4.5), civil rights (4.5), and separation of powers (3.5) impacts. The appeals court ruling enables termination of legal protections for 400,000+ migrants, representing major constitutional damage through: (1) rule of law - judicial validation of executive action to remove established legal protections, (2) civil rights - direct impact on due process and equal protection for vulnerable population, (3) separation of powers - judicial deference to executive immigration authority. Severity multipliers elevated (durability 1.2, precedent 1.2) due to appellate precedent affecting large population with limited reversibility. Mechanism modifier 1.15 for judicial action enabling executive policy. Scope modifier 1.2 for federal-level impact on broad population. B-score moderate (16.4) with outrage potential (7) and media friendliness (6) but limited meme-ability. Delta strongly positive (+29.7) clearly indicating List A classification.