Does a criminal defendant have a right to be personally present at the criminal proceedings?

Pursuant to the confrontation clause of the Sixth Amendment and the due process clause of the Fourteenth Amendment, a criminal defendant has a right "to be present at any stage of the criminal proceedings 'that is critical to its outcome if his presence would contribute to the fairness of the procedure.' " (People v. Bradford (1997) 15 Cal.4th 1229, 1356-1357.) "Defendant has the burden of demonstrating that his absence prejudiced his case or denied him a fair trial." (Id. at p. 1357.) Likewise, under California law, a person charged with a felony must be personally present at the arraignment, at the time of plea, during the preliminary hearing, during those portions of the trial when evidence is taken before the trier of fact, and at the time of the imposition of sentence. ( 977, subd. (b)(1).) At all other proceedings, the defendant must be present unless he or she has executed a written waiver. (Ibid.) Lack of a valid waiver is "nonprejudicial in situations where [the defendant's] presence does not bear a 'reasonably substantial relation to the fullness of his opportunity to defend against the charge.' " (People v. Garrison (1989) 47 Cal.3d 746, 782.)