Does the standard in Cuyler v. Sullivan, 446 U.S. 335 (1980), which requires only a showing that a conflict of interest adversely affected counsel's performance to establish a Sixth Amendment violation, apply to successive representation conflicts, as held by the Second, Third, and Ninth Circuits, or must defendants demonstrate prejudice under Strickland v. Washington, 466 U.S. 668 (1984), as required by the Fifth and Eleventh Circuits, with the Fourth, Seventh, and Eighth Circuits expressing uncertainty, given this circuit split?

When assessing adverse effect under Cuyler v. Sullivan for a conflict of interest, should courts apply a lenient standard focused on whether the conflict influenced counsel's strategic decisions, as adopted by the Second, Third, and Sixth Circuits, or a stringent "objective reasonableness test" requiring proof that an alternative strategy was factually viable, as applied by the Fourth and Eighth Circuits, which effectively mirrors Strickland's prejudice standard, creating inconsistent Sixth Amendment protections across circuits?

Does the Cuyler v. Sullivan standard for conflict of interest apply uniformly across circuits when assessing Sixth Amendment violations in successive representation scenarios?