Holy shit, I just heard of this one.

tl;dr a farmer grew "too much" wheat to feed animals on his own farm according to the government and even though he wasn't selling it SCOTUS said it still somehow constituted "commerce" because reasons.

The Court decided that Filburn's wheat-growing activities reduced the amount of wheat he would buy for animal feed on the open market, which is traded nationally, is thus interstate, and is therefore within the scope of the Commerce Clause.

That one needs a Dobbs reversal.