In a 2015 case upholding the constitutionality of Arizona's independent redistricting commission, a Supreme Court majority consisting of the four liberal justices and Justice Anthony Kennedy rejected the independent state legislature theory.
Notes on verification
Multiple independent, authoritative sources (SCOTUSblog, Ballotpedia, PBS, Wikipedia, Cornell LII) confirm the case citation, the 5-4 vote lineup, and the characterization as rejecting the independent state legislature theory. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.833 clusters=3 claim_tier=notable]
Sources
- What's at Stake When the Supreme Court Argues Moore v. ... (seed:politics_and_current_events)
- https://www.scotusblog.com/?p=500835 (corroboration)
- https://www.pbs.org/newshour/politics/justices-uphold-arizonas-system-redistricting (corroboration)
- https://ballotpedia.org/Arizona_State_Legislature_v._Arizona_Independent_Redistricting_Commission (corroboration)