Is a judge required to disqualify himself if his impartiality might reasonably be questioned?

A judge is required to disqualify himself if his impartiality might reasonably be questioned, see 28 U.S.C. Sec. 455(a), or if he has a personal bias or prejudice against a party, see id. Sec. 455(b)(1). Judicial remarks made during the course of a proceeding that are critical or hostile to a party or his case ordinarily will not support a bias or partiality claim unless they reveal an extrajudicial source for the opinion, or "such a high degree of favoritism or antagonism as to make fair judgment impossible." Liteky v. United States, 114 S.Ct. 1147, 1157 (1994).