Source: Institute for Justice
The state of Minnesota has an obscure statute that bans wineries from making wine unless the majority of the grapes used in their wine production are grown instate. This statute effectively imposes a trade barrier against out of state grapes. The drawbacks that result from this trade restriction are several fold. It forces wineries to use mostly grapes they grow in the harsh Minnesota weather, which makes it harder for them to expand their business, makes the wine more expensive and reduces the variety of wines they can produce for consumers. But most importantly, Minnesota's interstate trade restriction on out of state grapes is unconstitutional. Article 1 Section 8 gives congress the sole power to regulate interstate commerce. The dormant commerce clause implies, among other things, that states are prohibited from impeding interstate commerce by discriminating against out of state commerce. State's aren't allowed to restrict trade from other states for the same reason they aren't allowed to set their own immigration policies; they are not independent countries. Our federalist system delegates the authority necessary to maintain a country (e.g. national defense, immigration, trade policy) to the federal government and the rest is delegated to the states and municipal governments. Fortunately, the Institute for Justice has filed suit against the state of Minnesota on behalf of a handful of vineyards/wineries to overturn this statute.