Moore in many way is a mess, like most US Supreme Court Zoning cases. The reason for this is the Supreme Court likes avoiding two types of cases, Gun Control and Zoning cases. While various reasons are given for this avoidance, but the real reason is such cases are unpredictable for they both break up and realign the traditional Left-Right positions of the justices.
The reason for this is that these types of cases are more individual rights vs group right case than Group vs group rights. Right wingers who believe in small government and minimal government interference with business hate both Gun Control and Zoning, but economic right wingers like both for in zoning laws the VALUE of their property is enhanced by State action AND people who may take they property by force are restricted.
As to Liberals, liberals who like Government to help people like Zoning Laws (It provides places for EVERYONE in theory) and Gun Control (Restricts weapons to police who in theory protect EVERYONE). On the other hand liberals who prefer INDIVIDUAL FREEDOM hate both, for gun control restricts the freedom to defend one self in the matter one wants to, and Zoning law restricts HOW one can use one's own property.
(Please no comments on Gun Control, I am using it as example NOT to take a stand one way or another on that issue in this thread).
Even the first Zoning law case (VILLAGE OF EUCLID, OHIO v. AMBLER REALTY CO., 272 U.S. 365 (1926), (
http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=us&vol=272&invol=365) saw the opinion being written by one of the Most conservative men on the Court at that time (1926, Justice Sutherland) with the three Justices he almost always voted with being the dissent in Euclid. This as the classic split, the three dissenters wanted to reject Zoning for it interfered with how people could use their property, Sutherland and the majority valued Government Controls that ENHANCED property values over the individual right to use one's property as he or she saw fit.
This split continues to this day, it is a split that divides those people who value individual Rights from those that believe it is Government's role to enhance the Majority property value (and yet zone for everyone).
In Moore you saw Justice Burger going on and on that the case should be denied for the Grandmother should have gone and ask for a Variance of the Zoning Law instead of Challenging its Constitutionality (You can tell he did NOT want to rule on the merits of the case, he wanted to uphold the right of the town to pass any zoning restriction the town wanted, but at the same time did not want to rule that a Grandmother could, by that town, to force to kick out her orphaned 10 year old son, thus he went on and on about the failure of the Grandmother to ask for a Variance so her ten year old grandson could live with her). Two other justices were less concerned, they were more than willing to uphold the Zoning law for it preserved this suburb to the exclusive use of nuclear families.
Brennan and Marshall had the best argument, talking about the use of Extended families especially by Poor people (mostly black but also white poor people) and that such a Zoning rule would prevent such extended families from living under the same roof SOMETHING PEOPLE HAVE DONE FOR EONS except for the period since WWII.
The plurality decision just hanged its head on facts of the case, that the ten year old nearest relative was his 63 year old Grandmother and they did not want to rule the ten year old had no right to live with his grandmother under this Zoning Act and thus the Act was unconstitutional as applied to the ten year old and his Grandmother.
Notice NO MAJORITY DECISION IN MOORE, but it is clear that most of the Justice found it unfair to break up intake families.
Since Moore, the Court has ruled raising a family is a fundamental right (See TROXEL et vir. v. GRANVILLE,
http://caselaw.lp.findlaw.com/cgi-bin/getcase.pl?court=US&navby=case&vol=000&invol=99-138In Troxel, the Court ruled the State can NOT compel a Mother to leave the Paternal Grandparents see their Grandchildren if such visitation interferes with how the mother wants to raise her children (The Father was deceased so had no say in the raising of his Children after his death). The rationale for that decision was that Parents had a FUNDAMENTAL RIGHT to raise their children, the same argument made in Moore. In Troxel the Grandparents had won Visitation with their Grandchildren even when the Mother objected to the Visitation and it interfered with how the Mother wanted to raise her Children. The Court ruled such a STATE ORDERED visitation interfered with how the Mother was to raise her family and that was a Fundamental Right.
Basically Troxel backs up Moore that it is a fundamental right to keep one's family together and thus this statute prohibiting co-habiting people from living together WITH THEIR CHILDREN, is unconstitutional (Notice I avoided co-habituating people living without Children, that may NOT be covered by Moore and Troxel and more in line with Belle Terre v. Boraas.