Jonathan put it better: "Well, let's say that single mothers are more vulnerable to economic shocks and are more concerned about the safety net." Much more diplomatic. Single voters were a key demographic in 2012 (if the percentage of married voters had been what it was in 1980, Romney would have won) and there is little reason to imagine that their importance will wane in the future. Singles increased their share of the vote from 2008 by 6 points.
Until about 1970, the percentage of the adult population in America that was married never dipped below about 93 percent. Since then, marriage has been steadily declining. Today, about half the population is single. The unmarried represented about 40 percent of the electorate, and they broke heavily for Obama -- by 16 percentage points among single men and 36 percentage points among single women -- giving him two-thirds of his margin of victory. (By contrast, Romney prevailed among married voters by 56-42.)
The marriage gap is also an education gap in America. Those with little or no college, and particularly those without a high school diploma, are shunning marriage in favor of cohabitation. The college-educated, by contrast, are still marrying at close to the rates they did in the 1950s (though later in life, which contributes to lower fertility). Stable families among the elites perpetuate their status, providing their children with the financial and emotional stability necessary to lead fulfilling lives. Highly unstable families among the less educated lock in inequality, as well, prompting Charles Murray to call upon the elites to "preach what they practice."
It isn't a matter of urgent national importance when non-parents choose to live together without benefit of clergy (love the old fashioned expression). When children come into the picture, it is. There is simply no controversy about the data: Two-parent married families are best for children -- and best for society.
According to the Census Bureau, one of three American children grows up in a home without his biological father. These children are almost four times more likely to be poor (44 percent) as are children from intact families (12 percent).