What allowed the federal government to regulate a farmer's crop production in Wickard v. Filburn?

The regulation of a farmer's crop production in Wickard v. Filburn is primarily based on the effect on interstate commerce through supply and demand. The case revolved around a farmer, Roscoe Filburn, who was penalized for growing more wheat than the federal government allowed under the Agricultural Adjustment Act. Filburn argued that the excess wheat was for personal use and did not enter the market, suggesting it should not be subject to federal regulation.

However, the Supreme Court determined that even purely intrastate activities, like Filburn's wheat production, could have a substantial effect on interstate commerce. The reasoning was that by growing his own wheat and not purchasing it from the market, Filburn was contributing to a reduction in demand for wheat in interstate commerce. This created a ripple effect that could alter market prices and supply, thus justifying federal regulation of his production. The ruling established that Congress has the power to regulate local activities if they inevitably affect interstate commerce, illustrating the broad interpretation of the Commerce Clause. This case is a significant example of how federal regulatory power can extend to areas traditionally viewed as local or intrastate.