Temporal Unamendability
Temporality is best understood as a tertiary variation on unamendability. It is neither a primary category—like substantive or procedural unamendability—nor a secondary variation like formal or informal unamendability.
In any given constitutional regime, the forms of unamendability may be of either temporary or indefinite duration. For example, formal substantive unamendability may be entrenched temporarily, as we see in the United States Constitution,[84] or indefinitely, as we see in the German Basic Law,[85] subject of course to revision, replacement or revolution.[86] Likewise, formal procedural unamendability may be entrenched temporarily or indefinitely. A constitutional text may disable its formal amendment rules on procedural grounds for the duration of the regime, which is reflected in the Mexican Constitution,[87] or for a more limited period of time, a strategy the Cape Verdean Constitution illustrates by prohibiting formal amendment for 5 years after its coming-into-force.[88]Informal substantive and procedural unamendability may similarly be temporary or indefinite. A national high court could, for instance, interpret the constitution as anchored in inviolable unwritten principles that are immune from formal amend- ment—thereby entrenching informal substantive unamendability—but this decision is susceptible to refinement or reversal by a successor court. With regard to informal procedural unamendability, the political climate that gives rise to unamendability need not necessarily be permanent. It may evolve to either assuage or exacerbate the social, cultural, and economic conditions that have generated the political intractability that had given rise to informal procedural unamendability to begin with.
This classification we have proposed has an important limitation of its own.
The distinction between substance and procedure is not as clear as it might seem because substantive restrictions on formal amendment are often cast in procedural terms. Consider again the Mexican Constitution, which disables its formal amendment rules as to the entire Constitution in the event of rebellion. We have characterized this as an example of formal procedural unamendability because it entrenches a textual rule invalidating formal amendments affected during rebellion and does not expressly insulate the subject matter of a constitutional provision from formal amendment. Yet, we could alternatively characterize this prohibition as an example of formal substantive unamendability insofar as its actual though implicit purpose is to protect the content of the Constitution. The substance-process divide is thus less definitive than the classification suggests.Nonetheless, this classification is modestly useful because it complicates our understanding of unamendability. It demonstrates that unamendability may be textually entrenched or informally derived, and that it may concern the content of a constitutional rule or the process by which it may be altered. This classification moreover illustrates that a procedural limitation on formal amendment may conceal a substantive prohibition. In addition, this classification questions whether temporality should be a dominant category in defining the forms of unamendability. The result may admittedly raise more questions than answers, but it brings us closer to understanding how unamendability becomes entrenched in a constitutional regime.
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