In a 5-4 decision, the Supreme Court overruled Williamson County Regional Planning Comm'n v. Hamilton Bank of Johnson City, 473 U.S. 172 (1985) and held that owners aggrieved by state regulations they believe took their property without just compensation can immediately sue for relief in federal courts under 42 U.S.C. §1983 even if state law would have provided just compensation through administrative procedures. Knick v. Twp. of Scott, — U.S. — (2019). The line-up is what one would expect with Chief Justice Roberts and Justices Alito, Gorsuch, Kavanaugh and Thomas in the majority and Justices Kagan, Breyer, Ginsburg, and Sotomayor in the dissent. Roberts wrote the majority opinion and Kagan wrote the dissent. Thomas concurred.
The argument for allowing federal court relief is that it makes it realistically possible for federal courts to determine whether states have denied property without just compensation. Previously, the owner had to exhaust state remedies up through the state supreme court and then appeal to the US Supreme Court for relief. That final judgment could not then be challenged in federal court, effectively denying the owner any access to federal courts except through certiorari to the Supreme Court.
The argument in favor of retaining the Williamson County rule is that the Supreme Court has now opened the federal courts to what may be a flood of cases challenging local variance denials or applications of state wetlands or environmental regulations. This will not only make federal courts into the new zoning appeals board for every municipality in the country but require the courts to interpret state property law to determine whether "property" as defined by state law has been taken. It also places state and local officials in a difficult position since they are entitled to regulate, even to the point of effecting a taking, if it is for public use and compensation is paid but if every limit on property use imposed by a zoning, environmental, or historic preservation law generates a takings claim, then local officials may not be able to enforce those laws without paying compensation in advance. In other words, they may have to pay people to get them to obey the law, even if the law would not effectuate an unconstitutional taking. That may have the effect of unraveling local zoning and environmental laws – perhaps the point of allowing federal court cases challenging local property law decisions.
The problem is also that property regulations not only limit what you can do with your land but limit what your neighbor can do. They are popular because the protect property rights as much as they limit them. In the guise of a procedural ruling, the Knick case may have profound effects on property, zoning, historic preservation, disability access, and environmental law, especially when we consider the political and jurisprudential philosophy of judges that have been appointed to the federal courts in the last couple of years.