[spunkets]

"But production and local sales are not interstate commerce."

The local production and sale has an economic effect, because it is an integral subpart of what is in total an interstate market. If it's local hot dogs, it theoretically cuts in to the interstate market. The idea is uniform rules to maintain fairness in the market and protect the rights of the individuals involved. It is no stretch to see how simple rules providing for uniformity, fairness and rights protection are valid here.

[inquest]

If it's local hot dogs, it theoretically cuts in to the interstate market.

So what if it does? Congress is given the power to regulate interstate commerce, not protect it from competition.