In the past, it was dispersed rural interest groups who favored free trade, and concentrated urban producers who wanted protection for their new industries. Now, in the age of the knowledge economy, the relationship has reversed. Much of manufacturing now takes place outside of city centers. Ever since the New Deal and the rise of labor unions, manufacturing has been moving away from city centers and spreading out to exurban and rural areas along interstates, especially in the South. In an era of intense global competition, these have now become the places where voters can be most easily mobilized in favor of trade protection.
Moreover, much like manufacturing in an earlier era, the knowledge economy has grown up in a very geographically concentrated way in certain city centers. These are the places that now benefit most from globalization and free trade. We’re back to debates about trade and protection that occupied Alexander Hamilton and Thomas Jefferson, although the geographic location of the interests has changed over time. Changing economic geography has shaped our political geography in important ways, and contributed to an increase in urban-rural polarization.