That’s the title of an interesting piece at Quillette by Joel Kotkin. These passages especially caught my eye:

For progressives, the shift to post-familialism promises almost unlimited power, particularly in urban areas. Democratic pollster Stan Greenberg has noted that the singles, particularly single women, represent the Democratic Party’s largest core constituency, with two-thirds voting for Democrats. As families have fled from the largest cities—particularly their inner cores—the urban electorates have become almost Soviet in their voting patterns, with Democratic majorities upwards of 80 compared to 60 percent as recently as two decades ago. Overall in 2016, 52 percent of married people voted for Trump, while Clinton took 55 percent of the single vote.

Family formation and fertility rates of differing geographies could determine the election in 2020. The 11 states with the lowest fertility rates—including New York, California, and Massachusetts—are all hotbeds of progressivism, and unassailably Democratic. In contrast, all but one of the 25 states with the highest rates of fertility, from South Dakota to Kentucky and Texas, supported Trump and remain dominated by Republicans.

Emphasis added.