Anyone who’s lived in D.C. is aware of the city’s dirty secret: the wealthy northwest rarely engages with the swathe (地带) of low income people who share their city. In general, rich, college-educated white folks with decent, steady incomes are clustered in the northwest quarter. Their needs are serviced by a massive underclass, consisting largely of underprivileged immigrants, African-Americans, and Hispanics, that inhabits the remaining three quarters. Visitors to the city rarely glimpse this side of the city because there’s little reason to venture beyond the fancy hotels, restaurants, and attractions.Residents of D.C.’s northwest predominantly fit the class profile of those who wed later than average. Pew notes that populations with high rates of college education tend to wed later in life. Professional women also tend to be older when they wed. D.C. is virtually a one-industry town. Government and related industries employ almost all the white-collar workers, and that tends to attract lefty, progressive types who have a demonstrated proclivity (倾向) to marry later in life. Indeed, Pew of Washington City Paper found a correlation between states with a high proportion of Democratic voters and populations with a higher average wedding age. D.C. is overwhelmingly Democratic. Barack Obama received a whopping (巨大的) 92 percent of the vote last year；John Kerry received 89 percent in 2004; and A1 Gore grabbed 85 percent of the vote.Only around a third of D.C.’s population is white. African-Americans make up 56 percent of the population, and marriage rates among African-Americans have been steadily dropping since the 1960s. The last census found that just 36 percent of African American women were married, down from 62 percent in 1950. Marriage rates for white women also declined over the same period, but only from 66 percent to 57 percent. A large proportion of D.C.’s African-American community is low income or underemployed, both of which are indicators of low marriage or high divorce rates.Lastly, even though D.C. is home to world-class universities, think tanks, and thought leaders, a shockingly high 37 percent of its population is functionally illiterate. That’s around 15 percentage points higher than the national average. It goes without saying that literacy rates and poverty are strongly correlated. There’s also much scholarship highlighting the declining rates of marriage in poor communities. Harvard’s Kathy Edin, for example, has produced fascinating work on the tendency of poor women to put motherhood before marriage. According to Pew, people intending to marry later in life are those who receive （）.