[robertpaulsen]

"but other courts since have regarded the decision as saying that anyone who grows any commodity which is involved in interstate commerce is subject to federal government control, even if they themselves never put their commodity into the general interstate market."

That's not what they said.

Congress, through the power of the Necessary and Proper Clause (Article 1, Section 8, Clause 18), may legislate intrastate activity that has a substantial effect on the interstate commerce that Congress is currently, and constitutionally, regulating.

The Necessary and Proper Clause must be used in conjunction with another Article I, Section 8 power -- it is not a stand-alone, carte blanch power.