What is the test for judicial disqualification under the due process clause?

""While a showing of actual bias is not required for judicial disqualification under the due process clause, neither is the mere appearance of bias sufficient. Instead, based on an objective assessment of the circumstances in the particular case, there must exist '"the probability of actual bias on the part of the judge or decisionmaker [that] is too high to be constitutionally tolerable."' [Citation] Where only the appearance of bias is at issue, a litigant's recourse is to seek disqualification under state disqualification statutes: 'Because the codes of judicial conduct provide more protection than due process requires, most disputes over disqualification will be resolved without resort to the Constitution.' [Citation.] Finally, . . . only the most 'extreme facts' would justify judicial disqualification based on the due process clause." (People v. Freeman (2010) 47 Cal.4th 993, 996.)