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

"Under state and federal law, a defendant has a due process right to an impartial trial judge." (People v. Peoples (2016) 62 Cal.4th 718, 787.) "[W]hile 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.]" (People v. Freeman (2010) 47 Cal.4th 993, 996.) Only the most "extreme facts" justify judicial disqualification based on the due process clause. (Ibid.)