Within-state geographic shifts are significant given that in many swing states, the metro area vote share is so large that if the Democrats win enough urban and suburban voters, Republicans cannot count on enough exurban and rural voters to win statewide elections. 4 The same can be said for the migration of Democratic-leaning voters from places such as California into red state major metro areas (such as Austin, Texas) and the impact the new residents have on statewide election outcomes. In the election’s aftermath, the role of density and the exodus of college-educated suburbanites from the GOP has received significant attention. Democrats’ increasing support among higher-educated voters helped the party push further into the suburbs-particularly those that are diverse, urban, and well educated. Indeed, while it has long been the case that density and diversity predict Democratic support, 3 the results suggest that another “D” can be added to that axiom: degrees. We find that the elections accelerated the trends we identified. In this brief, we assess how well the book’s main hypotheses fared in the 2020 presidential and the 2021 Georgia U.S. By focusing our analysis on swing states, we examine these dynamics in contexts that determine the partisan balance of power at the federal level. 2 Blue Metros, Red States placed these tensions in a common geographic framework-the million-plus population metro area compared to the rest of a state’s population-and considered how these economic and demographic powerhouses navigate their state’s often hostile political terrains. The end result, as journalist Ron Brownstein noted after the 2016 election, has been a decoupling of demographic and economic power from political power. Senate and the Electoral College policies and processes such as redistricting, home rule, and preemption and metro area fragmentation often disadvantage urban and suburban interests. The attitudinal differences also have implications for perceptions of status loss, particularly among white residents. There are also sharp attitudinal differences due to rising negative partisanship and the growing saliency of cultural, racial, and other diversity-related issues. Next is demographic and economic sorting that concentrates diversity and economic productivity in the country’s largest metro areas. First are sociocultural factors often determined by initial settlement patterns and that shape values and attitudes related to diversity acceptance. Within-state splits derive from four interrelated influences.

The book covered 13 swing states that had a 2016 presidential race margin of 10 points or less and contain at least one metropolitan area exceeding 1 million residents. We argue that movement toward the Democratic Party in rapidly urbanizing suburbs is shifting America’s partisan fault line from a long-standing urban-rural divide to an emerging split between metro areas and the rest of state.

Last year, the Brookings Institution Press published our book, Blue Metros, Red States: The Shifting Urban-Rural Divide in America’s Swing States. Differences within states also anchor the long-standing urban-rural divide-a salient feature of American politics since the country’s founding. But despite its ubiquity, this structure ignores how intrastate regional tensions and political competition imbue the divisions between red and blue America. Since at least the 2000 presidential election, pundits, scholars, and the general public have conceptualized the country’s partisan landscape using the blue states, red states, and swing states framework.

Us electoral map by population density