This event represents routine political posturing during a government shutdown rather than constitutional damage. The refusal to change filibuster rules is actually maintenance of existing norms, not erosion. A=0.19 reflects minimal constitutional impact: rule_of_law:1 (minor procedural dysfunction), separation:2 (shutdown reflects inter-branch tension but is constitutional mechanism). Mechanism modifier 0.4 applied because 'norm_erosion_only' tag is misapplied - NOT changing rules preserves norms. B=13.69 reflects moderate media attention to shutdown drama with strategic mismatch (framing inaction as crisis). D=A-B=-13.5. Classification: Noise because A<25, no actual mechanism of damage (preserving filibuster protects minority rights), and this is routine shutdown politics that occurs periodically without lasting constitutional impact.