Due Process Requires Adequate Criminal Appeals / McKane Must Be Retired
"[M]en who were wisely democratic for the sake of harmony, ordained that no magistracy should be created without the right of appeal."---Marcus Tullius Cicero
A review by an appellate court of the final judgment in a criminal case, however grave the offense of which the accused is convicted, was not at common law, and is not now, a necessary element of due process of law. It is wholly within the discretion of the state to allow or not to allow such a review. A citation of authorities upon the point is unnecessary.
Legal authorities would then have seemed unnecessary, given that due process was required in federal courts by the Fifth Amendment , but there never had been a criminal right of appeal in federal courts. This was fixed by the Criminal Appeal Act of 1907, and it is now high time that McKane was retired.
In Cleburne v. Cleburne Living Ctr., Justice Marshall observed that "history makes clear that . . . constitutional principles of liberty, property, and due process, evolve over time; what once was a 'natural' and 'self-evident' ordering later comes to be seen as an artificial and invidious constraint on human potential and freedom."  The Supreme Court particularly recognized the "evolving standards of due process " in Kulko v. Superior Court,  and in Jiminez v. Myers ,  Ninth Circuit Judge Kozinski lauded the nation's "truly federal system where the state courts serve as laboratories for shaping the flexible and evolving standards of due process."
Nevertheless, even though every state and federal trial court has provided a criminal right of appeal for well over one hundred years,  the Supreme Court continues to affirm that constitutional due process, which applies to the states through the Fourteenth Amendment , does not guarantee such a right. Thus, in 2005 the majority in Halbert v. Michigan convolutedly held:
The Federal Constitution imposes on the States no obligation to provide appellate review of criminal convictions. McKane v. Durston , 153 U. S. 684, 687 (1894). Having provided such an avenue, however, a State may not "bolt the door to equal justice" to indigent defendants. Griffin v. Illinois , 351 U. S. 12, 24 (1956). ) (Frankfurter, J., concurring in judgment); see [several citations.] 
The minority in Halbert applied the 1894 McKane precedent with a pejorative present-day twist (at 631):
Michigan is under no constitutional obligation to provide appeals for plea-convicted defendants. Ante, at 610 (citing McKane ). Michigan may decline to provide an appellate process altogether . Surely plea-convicted defendants would prefer appeals with limited access to counsel than no appeals at all.
It might seem that the failure to incorporate a criminal right of appeal in the constitution's due process requirements doesn't matter, since a right to appeal is now universally provided, which, under the constitution's equal protection clause, cannot be denied to anyone.  Because of this, the constitutional due process question has not been revisited. However, the Supreme Court's regular recitation of the obsolete constitutional doctrine indicates that it does matter, and not only because of its jarring twenty-first century incongruity.
As in Halbert, formulaically reaffirming the lack of any constitutional right of appeal operates as an inconvenient and pejorative preliminary in deciding concomitant postconviction rights. Worse, it invidiously perpetuates a spurious division in inherently integrated trial-cum-appellate verdict-cum-sentencing regimes, of the sort mandated in Furman v. Georgia,  which in 1972 conditionally nixed the death penalty nationwide. Worst, there is no equal protection substitute for due process where, as is evidently now the case re many state death penalty regimes, appellate processes are systemically dysfunctional, so that each and every litigant's right to appeal is impartially impaired. A state is therefore free to dial-down its appellate, but not its trial,  processes, regardless of the degree to which the right of criminal appeal is thereby devalued, up to and including its formal extinction.
Justice Frankfurter's above-quoted 1956 concurrence recognized the likelihood that constitutional due process would ultimately incorporate the criminal right to appeal (Griffin, at 20-21):
The admonition of de Tocqueville not to confuse the familiar with the necessary has vivid application to appeals in criminal cases. The right to an appeal from a conviction for crime is today so established that this leads to the easy assumption that it is fundamental to the protection of life and liberty and therefore a necessary ingredient of due process of law. 'Due process' is, perhaps, the least frozen concept of our law--the least confined to history and the most absorptive of powerful social standards of a progressive society. But . . . no appeals from convictions in the federal courts were afforded for nearly one hundred years . . . Thus, it is now settled that due process of law does not require a State to afford review of criminal judgments . . . McKane .