The case or controversy requirement of Article III, Section 2 of the U.S. Constitution, which constitutes “the irreducible constitutional minimum of standing,” requires that a plaintiff show: The party asserting federal jurisdiction bears the burden of establishing these requirements at every stage of the litigation, as it does for “any other essential element of the case.” On appeal from a motion to dismiss, a plaintiff need only show that the facts alleged, if proven, would confer standing.