Did the Ninth Circuit err when it denied States with sufficient interests the ability to intervene as defendants after the federal government stopped defending its own rule

QUESTION PRESENTED This case presents the same question on which this Court granted review in Arizona v. City & County of San Francisco, No. 20-1775, and Arizona v. Mayorkas, No. 21-592. In both cases, this Court was ultimately unable to resolve the question of whether the federal government can implement rules by acquiescing to collusive “settlements” in litigation. The Court granted certiorari then to decide whether States could intervene and oppose these “sue and settle” arrangements. Here, the federal government originally, and vigorously, defended its Circumvention of Lawful Pathways rule against challenges from various interest organizations. It did so at the district court, and it did so in the Ninth Circuit. Then came the “surprising switcheroo”: The federal government “gave up its defense of the rule and entered into settlement negotiations.” App.18, 21 (VanDyke, J., dissenting). Petitioners promptly sought intervention to protect their interests in the Rule by participating in these settlement negotiations. In a 2-1 decision, the Ninth Circuit denied intervention, setting the stage for yet another Arizona uv. City & Cnty. of S.F.,596 U.S. 763, 766 (2022) (Roberts, C.J., concurring) (citation omitted). The question presented is: Did the Ninth Circuit err when it denied States with sufficient interests the ability to intervene as defendants after the federal government stopped defending its own rule.