A Theory of Constitutional Viability Basin Loss, Hysteresis, and Spatial Cascades

A constitution may remain legally valid while the system operating beneath it ceases to occupy a state in which its constraints can generate a stable political regime. This article develops that distinction as a theory of constitutional viability. The Federalist is treated not as a source of mathematics but as a constitutional architecture of energy, constraint, counteraction, and judgment. A nonlinear slow-fast model then represents the conditions under which a stable constitutional operating regime exists, disappears, and may or may not be recovered. Numerical stress tests of the stated model produce four results. First, a high-capacity equilibrium can terminate in a genuine saddle-node while the formal constitutional threshold remains fixed. Second, slow deterioration produces delayed departure after the static fold. Third, after repairing the social-capacity equation so that the physical state space is forward invariant, cooperative restoration generates a measurable hysteresis interval: the vulnerability level at which a viable regime collapses differs from the level at which a depleted regime becomes recoverable. Fourth, spatial coupling can transmit vulnerability across jurisdictions, so local basin transitions can become regional cascades. Lyapunov functions provide a complementary certificate: bifurcation analysis identifies when a viable equilibrium ceases to exist, while local Lyapunov inequalities identify whether disturbances decay while it exists. The theory therefore separates constitutional validity, compliance, viability, resistance, and recoverability.