After the amendment, the FLSA applied equally to all state employees including those in hospitals and schools which are areas typically thought to be outside the penumbra of "interstate commerce" regulatory powers.

However, the Court distinguished the case from Darby, explaining that the 10th amendment declares that Congress cannot exercise its power so as to impair the states' integrity or their ability to function effectively in a federal system.

The majority abandoned the reasoning applied in Maryland v. Wirtz[6] and cited the fears of unchecked power expressed by Justice Douglas in his dissent.

The majority also mentioned that the FLSA's requirements would force states to restructure many of their existing policies, and would result in a substantial cost burden.

Blackmun was later the swing justice who switched sides and helped overturn the case, asserting that the "traditional government functions" test he had previously supported had proved "unworkable."