If you've listened to a politician talk for at least 5 seconds you've probably heard the term middle class. It contrasts with Marxist ideas about society being divided into two classes with opposing interests: the tiny bourgeoisie which can survive entirely from its ownership of capital, and the great mass of proletariat, which must sell its labor to survive. The "middle class" is regarded by many as one of those warm and fuzzy unquestionably good things, like apple pie cooling on a windowsill and baseball. What exactly it means, besides not too rich, not too poor, I'm not exactly sure. There's no universally accepted definition. However, a lot of it seems to have to do with homeownership.
As a whole in 2008, of America's 75.4 million owner-occupied housing units, 81.8% were detached single family homes (the building blocks of suburbia), 6.8% were mobile homes, 5.8% were attached rowhouses, and only 1.9% were apartments in the largest buildings (with 20 or more units). These data come from the Census Bureau's American Community Survey (ACS) one-year estimates.
Hence, the kind of density I advocate for isn't doing too well on the homeownership side. In future posts on this topic I intend to explore whether or not that matters, and if so, whether or not it is inevitable.