In a post-election interview with the Milwaukee Journal-Sentinel, Paul Ryan, chairman of the House Budget Committee and the GOP’s 2012 vice presidential nominee, said “the president should get credit for achieving record-breaking turnout numbers from urban areas for the most part, and that did win the election for him.” Ryan’s critics noted that President Barack Obama also fared well in states like Iowa, where the urban vote is relatively small. Some even suggested that Ryan’s remarks were a kind of racial code, in which “urban areas” served as a stand-in for black and Latino voters. Yet Ryan’s observation speaks to a deeper truth that should trouble Republicans.

Although rural regions dominate the map of the contiguous United States, an overwhelming majority of Americans live in urban and suburban areas. Democrats have long dominated dense urban cores. But Democrats increasingly dominate dense inner suburbs—as opposed to sprawling outer suburbs, where Republicans still hold their own—as well, and the share of the population concentrated in dense suburban counties is steadily increasing. This is true not only among Latino, black, and Asian voters living in these communities, but of white voters as well.

Consider, for example, the political trajectory of Fairfax County in northern Virginia, a dense suburban county with a population of 1.1 million that lies just across the Potomac from Washington, D.C. As recently as 2000, the GOP presidential candidate George W. Bush won Fairfax with 48.9 percent of the vote to Al Gore’s 47.5 percent. In 2004, though, Bush lost Fairfax to John Kerry 45.9 percent to 53.3 percent. Barack Obama won Fairfax by an overwhelming 60.1 percent in 2008, and he won it again by an only slightly less overwhelming 59 percent in 2012. One of the most striking numbers from Fairfax is that George W. Bush’s winning vote total in 2000 — 202,181 — is an eerily close match for Mitt Romney’s losing total in 2012 — 206,733. It just so happens that Obama won 315,273 votes in 2012. And Fairfax is hardly alone. Orange County, California—once  a hotbed of Goldwaterite conservatism—backed Mitt Romney by 51.9 percent of the vote, a sharp decline from the 55.8 percent support George W. Bush received in 2000. You’ll find the same pattern in Wake County, North Carolina, DuPage County, Illinois and Jefferson County, Colorado and other populous inner suburban counties across the country. In The Emerging Democratic Majority, John Judis and Ruy Teixeira referred to these communities as post-industrial “ideopolises,” in which economic life revolves around college-educated professionals working in knowledge-intensive services and the less-skilled workers who meet their various needs.

Rather than fixate on ethnicity, conservatives would do well to think more about urbanity. What is it about life in America’s densest, most productive, and most economically stratified metropolitan areas that persuades voters to back Democrats? When this phenomenon was limited to the populous coastal metropolitan areas, it could reasonably be explained away as a product of regional political polarization. But the leftward trend in urban areas is chipping away at the GOP’s advantage in the South and the Mountain West as well.

Among conservatives, there is a broad post-election consensus that America’s demographic transformation represents a serious challenge for a Republican Party that is disproportionately backed by white Anglos and voters over the age of 65. Thus many on the right have called on congressional Republicans to embrace comprehensive immigration reform as part of a larger effort to woo Latino voters. The pushback has been that Latino voters tend to be less affluent and more likely to rely on anti-poverty programs such as SNAP and Medicaid, and so it is hardly surprising that they are more inclined to support Democrats. What is more striking, however, is that Asian-American voters, a relatively affluent group, favored Obama by 73 percent to 26 percent. One possible explanation is that Asian-Americans are heavily concentrated in dense coastal regions, where they vote much like white Anglos with similar educational profiles and religious beliefs. That is, secular college-educated Asian Americans appear to be about as hostile to the GOP as secular college-educated white Anglos, which is to say very much so.