Privileges and Immunities Clause of Article IV, Section 2: "The citizens of each state shall be entitled to all privileges and immunities of citizens in the several states."

To show that a state law (or a municipal ordinance) violates the Privileges and Immunities Clause of Article IV, Section 2, the challenger must satisfy three preliminary hurdles:

A. The state law must treat differently citizens (residents) and noncitizens (nonresidents) of the state and discriminate against noncitizens (nonresidents); and

B.  The state law must be challenged by a flesh and blood nonresident of the state rather than a corporation or other artificial entity; and

C. The discrimination must adversely affect a fundamental privilege or immunity of state citizenship. The question is whether the activity the nonresident is seeking to engage in is one that is "fundamental to the promotion of interstate harmony."  Activities that involve access to private employment opportunities have been found to be fundamental or essential activities protected by Article IV, Section 2 while recreational activities have been found not to be protected by the Clause. In addition, government employment has been held not to be a privilege or immunity protected by the clause while private employment has been found to be protected. In general, the Clause has been viewed as protecting the right of nonresidents to participate in the private commercial marketplace by buying and selling goods, buying and selling property, getting a job, and pursuing other economic opportunities. The extent to which the Clause protects other kinds of rights is unclear. In addition, the Court has recently announced that a discriminatory law will only violate the Privileges and Immunites Clause of Article IV if it has a protectionist purpose and not if has a discriminatory effect but lacks a discriminatory purpose: "[T]he Clause forbids a State from intentionally giving its own citizens a competitive advantage in business or employment."

If a court concludes the challenger has satisfied the three preliminary hurdles, the burden shifts to the state to satisfy a two part test:

1. Does the state have a substantial reason for treating nonresidents differently? (are nonresidents a peculiar source of the evil); and

2.  Does the degree of discrimination against nonresidents bear a substantial relation to the state's objective? This includes a consideration of the availability of less restrictive means (Supreme Court of New Hampshire v. Piper).

In this analysis, unlike under the dormant Commerce Clause, there is no exception when the state is acting as a market participant (United Building & Construction Trades Council v. Mayor and Council of Camden).