Going over some of the court cases that I have saved over the years, this one is a very good read.
Where I have it highlighted is irrelevant, because in going back over it today I see there are more quotes I can highlight.
However, I find the best quote in this decision is:
States are not
mere political subdivisions of the United States. State governments are neither regional offices nor administrative agencies of the Federal Government. The positions occupied by state officials appear nowhere on the Federal Government's most detailed organizational chart. The Constitution instead "leaves to the several States a residuary and inviolable sovereignty," The Federalist No. 39, p. 245 (C. Rossiter ed. 1961), reserved explicitly to the States by the Tenth Amendment.
Whatever the outer limits of that sovereignty may be, one thing is clear: The Federal Government may not compel the States to enact or administer a federal regulatory
program.