The Constitution generally regulates what government may do, not what private individuals or entities may do to one another. Before a court will reach the merits of most constitutional claims, a plaintiff must clear a threshold requirement: showing that the conduct being challenged counts as state action -- conduct fairly attributable to the government -- rather than purely private conduct that the Constitution does not reach directly.

No single formula resolves every case. Courts have developed several overlapping tests for finding state action in conduct performed by nominally private parties, and which test applies, and how it comes out, often depends heavily on the specific relationship between the private actor and the government.

The state-action requirement preserves a zone of private ordering: it prevents constitutional litigation from becoming a general-purpose tool for policing private behavior, and it reflects the premise that constitutional constraints exist because government uniquely wields the state's coercive and regulatory power. Private discrimination, private contractual disputes, and private torts, however wrongful, are ordinarily left to other bodies of law rather than constitutional claims.

Courts have applied several approaches, including a public-function test (asking whether a private party performs a function traditionally and exclusively reserved to government), a close-nexus or joint-action test (asking whether the government is so entangled with the private actor's decision that the two are effectively acting together), a government-compulsion test (asking whether the government coerced or significantly encouraged the private conduct), and an entwinement test (asking whether the structural relationship between public and private actors is pervasive enough to treat the private actor as the government for that purpose).

A plaintiff builds the state-action case with evidence of funding, regulatory control, joint decision-making, contractual delegation of a government function, or symbiotic institutional relationships. A defendant resisting the claim emphasizes independent private decision-making, arm's-length dealings with government, and the absence of coercion or significant encouragement -- arguing the challenged decision was its own, not the state's.

Because state action is a gate that must be cleared before any constitutional claim can proceed at all, it functions as the first decision node in a constitutional claim path -- upstream of qualified immunity, Monell liability, or any substantive due process or scrutiny analysis. In Juricratic terms, a claim can be modeled with the strength of the state-action nexus as its own dial: adjusting it shows how the viability of the entire downstream claim matrix depends on clearing this threshold, separately from the strength of the underlying constitutional theory.

These dials describe how a claim's structure can be explored, not a projection of a real court's ruling.