Whether automatic reversal is required when a defendant's plea was not knowingly and intelligently made in violation of the Due Process Clause

QUESTIONS PRESENTED FOR REVIEW (1) When it is undisputed that a defendant’s plea was not knowingly and intelligently made in violation of the Due Process Clause, is automatic reversal required? (2) Relatedly, what prejudice inquiry (if any) applies to appellate review of an unknowing and involuntary guilty plea? (3) Whether the constitutional error satisfied the substantial-rights prong of plain error as applied by the court?