IN A MORE agricultural era, America’s West and Midwest seemed like the promised land. Starting in the mid-19th century, the federal government distributed free land to settlers who were willing to brave the tribulations of frontier life to forge a new beginning. Today, however, services make up the bulk of the American economy, and rural regions are facing two demographic challenges. First, more people are moving out than are moving in. And to make matters worse, highly educated residents make up a disproportionate share of the leavers. States in the middle of the country contain an outsized share of residents without college degrees, whereas those on the coasts suck up the educated high-fliers, with some exceptions (Texas has been able to buck the trend, largely thanks to a budding tech sector). Economic opportunity has shifted accordingly.

Although the depopulation of America’s “heartland” is well-known, the internal redistribution of educated professionals —so-called“brain drain”—poses new economic, social and political difficulties for affected areas. Updated for 2017, new data from Congress’s Joint Economic Committee show that most states in the Rust Belt, Southeast and Plains regions are losing their educated residents to coastal states, as well as to Texas and Illinois. For example, people who move to California are 20 percentage points more likely to be among the most educated third of Americans than people who leave it are. Conversely, people relocating to Pennsylvania were ten percentage points less likely to be in the top third than those moving out.

The consequences of a prolonged brain drain could be dire. Because America’s electoral system over-represents small states, the less-educated people living in places with shrinking populations could become more politically influential, even as their numbers decline.