519 F.3d 909 (9th Cir. 2008) Cited 1,083 times
Holding that the two-part test is whether "a reasonable third-party observer who "understand all the relevant facts" and has examined the record and law—not a "hypersensitive or unduly suspicious person"—would conclude that there is an appearance of bias, and whether the court concludes that it cannot impartially "administer justice without respect to persons."