This item (the link expires tomorrow) about U.S. restrictions on avocado imports from the Dominican Republic (hey, these other guys are talking about cartoon characters on the Supreme Court!) highlights the falsity of the libertarian claim that free trade and free immigration go together. Not only is this false as a matter of theory (see here or scroll down to Assumption 4 here), it doesn’t work this way in reality either. In fact, the linkage that would appear strongest is between open immigration and protectionism. The reason is that both are subsidies for business — we see this especially in agriculture, where farmers get the government to keep out the foreign avocados (or winter tomatoes or whatever) and import foreign workers instead.