The P&I clause of the 14th Amendment is the constitutional provision that prevents one state from requiring a passport of a traveling citizen of another state. The idea of invoking it to limit the power of states to grant effective monopolies to local businesses arose shortly after it was enacted, but in 1873 the Supreme Court rejected P&I as a source of right to engage in a business, limiting protected privileges to those that are inherently federal in origin. The loss is more theoretical than real, given the state-limiting power of the Commerce Clause.

Today, privileges thought to fall within the P&I clause include passing freely from State to State, petitioning Congress for a redress of grievances, voting for national officers, entering public lands, being protected against violence while in the lawful custody of a United States marshal, and informing federal authorities of violation of federal law. There is a 19th century case that includes the right to engage in an interstate business, but it may be unnecessary to revive that theory in view of the robust protection provided by the Commerce Clause. The Siesta Village court explicitly nixes the local citizenship requirement on location inequality grounds, which are based on Commerce Clause requirements articulated in Granholm and in numerous cases on which Granholm relies.