Several groups allege they suffered damages from a town ordinance that is assumed, for purposes of the opinion, to exclude low-income persons and thereby to violate their rights. Some allege exclusion of themselves from living in the town. Others allege harm in the form of taxes increased by insufficient building of low-income housing; still, others allege harm as part of an association - with members either part of a group already indicated, or part of a residential construction firm, or town residents. Petitioners, Warth (P) assert ` 11 that they unsuccessfully sought low-income housing but do not allege facts implying that in the absence of the ordinance and enforcement thereof they would probably have been able to make the necessary purchase or lease. Instead, they allege that developers, builders and the like, against whom the ordinance was enforced, have been induced to refrain from construction of the desired housing. Taxpayers base their claim on the rights of low-income persons. Construction firm petitioners allege no specific project precluded by the ordinance. Residents purport to seek racial/ethnic diversity but are thereby asserting indirect harm resulting from denial of third parties' rights. All claim that their constitutional and statutory rights have been violated. The lower courts held that none of the Ps have standing.