I've long been sympathetic to the argument, advanced over the years in various forms by members of the Greeberg Quinlan Rosner team, that the "marriage gap" is an under-recognized feature of American politics and that one of liberalism's most promising growth areas is simply in finding better ways to engage and mobilize unmarried women who are a large and quite progressive bloc of the population with low voter turnout rates. You can see the latest form of the argument in this report and, as I say, I find it convincing.
I do, however, keep being disappointed by the relative lack of statistical sophistication you see here. After all, unmarried people are demographically quite different from married people in a number of ways including age, race, sexual orientation and religious affiliation — all characteristics that are plausibly big driver's of voting behavior. They do a decent job of showing that the "marriage gap" holds up even when you look at the major sub-samples of the population (it's not, in short, just driven by the different marriage rates of blacks, whites, and Latinos) but this is still a pretty crude way of looking at the interplay of factors. What would really be nice would be some regression analysis that could help us try to estimate the impact of marriage independent of other demographic factors.
Relatedly, it's always worth saying that proposals to "target" this or that slice of the electorate sometimes seem to me to involve underestimating the heterogeneity of the group. It's true, for example, that one would expect a 25 year-old unmarried white woman who graduated from Wellesley, took an entry-level job at a DC think tank, and is now enrolled at Georgetown Law School and a 25 year-old unmarried African-American mother of two who dropped out of high school to both be loyal Democrats but it's not at all clear that there's a common "single woman" or even "single 25 year-old woman" characteristic that's driving this common voting behavior, even though they're both common archetypes in major American cities. A Republican strategist looking to make inroads with these voters, for example, would probably adopt different strategies depending on which woman they were trying to court.