When will a structural error rule apply and require a reversal of a judgment without inquiry into whether any harm occurred?

^5. We reject defendant's argument that the "structural error rule" should apply and require automatic reversal of the judgment without inquiry into whether any harm occurred in order "to ensure the 'essential demands of fairness' and to prevent 'invidious discrimination on the basis of race.' (Ham [v. South Carolina (1973)] 409 U.S. [524,] 526-527 [(Ham)]." As defendant acknowledges, Ham does not hold that the structural error analysis applies in a case, like his, where a criminal defendant challenges the adequacy of a trial court's voir dire on due process grounds. (Ham, at pp. 526-529.) A decision is not authority for issues not considered. (People v. Knoller (2007) 41 Cal.4th 139, 154-155 [" 'An appellate decision is not authority for everything said in the court's opinion but only "for the points actually involved and actually decided" ' "].) Defendant directs us to no on-point authority supporting his argument; nor do we know of any.