What is the current state of the law on judicial bias and partiality?

Constitution.' [Citation.] Finally,... only the most 'extreme facts' would justify judicial disqualification based on the due process clause. [Citation.]" (People v. Freeman (2010) 47 Cal.4th 993, 996.)

"On appeal, we assess whether any judicial... bias was so prejudicial that it deprived defendant of ' "a fair, as opposed to a perfect, trial." ' [Citations.]" (People v. Guerra, supra, 37 Cal.4th at p. 1112.)

As the United States Supreme Court has explained "opinions formed by the judge on the basis of facts introduced or events occurring in the course of the current proceedings, or of prior proceedings, do not constitute a basis for a bias... unless they display a deep-seated favoritism or antagonism that would make fair judgment impossible. Thus, judicial remarks during the course of a trial that are critical or disapproving of, or even hostile to, counsel, the parties, or their cases, ordinarily do not support a bias or partiality challenge. They may do so if they reveal an opinion that derives from an extrajudicial source; and they will do so if they reveal such a high degree of favoritism or antagonism as to make fair judgment impossible. An example of the latter (and perhaps of the former as well) is the statement that was alleged to have been made by the District Judge in Berger v. United States, 255 U.S. 22, 41 S.Ct. 230, 65 L.Ed. 481 (1921), a World War I espionage case against German-American defendants: 'One must have a very judicial mind, indeed, not [to be] prejudiced against the German Americans' because their 'hearts are reeking with disloyalty.' [Citation.] Not establishing bias or partiality, however, are expressions of impatience, dissatisfaction, annoyance, and even anger, that are within the bounds of what imperfect men and women, even after having been confirmed as federal judges, sometimes display." (Liteky v. U.S. (1994) 510 U.S. 540, 555-556.)