The Supreme Court has, on occasion, described incompetence in terms of a right not to be tried.
E.g., Godinez v. Moran, 509 U.S. 389, 396 (1993) (“A criminal
defendant may not be tried unless he is competent.”);
Drope, 420 U.S. at 171 (holding that an incompetent defendant
“may not be subjected to a trial”); id. at 172 (describing
“a defendant’s right not to be tried or convicted while incompetent”).
The Supreme Court, however, has never held that incompetency includes an absolute right not to be tried, or that a competency determination cannot be reviewed effectively on appeal after conviction. On the contrary, the Court has said that “[d]ouble jeopardy and speech or debate rights are sui generis in this regard.” Flanagan, 465 U.S. at 267, 104 S.Ct. 1051; see also Mohawk Indus., Inc. v. Carpenter, 558 U.S. ----, 130 S.Ct. 599, 602, --- L.Ed.2d ---- (2009) (“[T]he class of collaterally appealable orders must remain ‘narrow and selective in its membership.’ ” (quoting Will v. Hallock, 546 U.S. 345, 350, 126 S.Ct. 952, 163 L.Ed.2d 836 (2006))). At base, incompetency concerns a right to a fair trial. See Drope, 420 U.S. at 172, 95 S.Ct. 896 (“[T]he failure to observe procedures adequate to protect a defendant's right not to be tried or convicted while incompetent to stand trial deprives him of his due process right to a fair trial.”). That right can be protected adequately by post-conviction appellate review.
Due process of law is defined in procedural cases by the Supreme Court with full consideration to what society considers wrong and unfair.
Justice Frankfurter, who contributed greatly to the definition and expansion of procedural due process, stated in 1950:
Whenever a judge acts where he/she does not have jurisdiction to act, the judge is engaged in an act or acts of treason. U.S. v. Will, 449 U.S. 200, 216, 101 S.Ct. 471, 66 L.Ed.2d 392, 406 (1980); Cohens v. Virginia, 19 U.S. (6 Wheat) 264, 404, 5 L.Ed 257 (1821).
I have an obligation to fix a sentence that provides appropriate
and just punishment; that will serve to incapacitate you, to the
extent that is necessary, . . . and appropriate to protect the public.
