What is the current state of the law on waiver of counsel in a criminal case?

Federal authority holds that once a defendant gives a valid waiver, it continues through the duration of the proceedings unless it is withdrawn or is limited to a particular phase of the case. "While it is true that the Sixth Amendment right to counsel applies at all critical stages of the prosecution, including the sentencing stage, it does not follow that once the assistance of counsel in court has been competently waived, a new waiver must be obtained at every subsequent court appearance by the defendant. A competent election by the defendant to represent himself and to decline the assistance of counsel once made before the court carries forward through all further proceedings in that case unless appointment of counsel for subsequent proceedings is expressly requested by the defendant or there are circumstances which suggest that the waiver was limited to a particular stage of the proceedings." (Arnold v. United States (9th Cir.1969) 414 F.2d 1056, 1059.)