Partisanship runs deep these days. But it’s not just ideas that divide the country. Increasingly, family formation is becoming a wedge between Left and Right. Following the 2024 election, Lyman Stone and I found that Republican-leaning counties are having more children than Democratic counties, and the gap is growing. The top 20% most Republican counties had a total fertility rate of 1.76, compared to the most Democratic counties which had a total fertility rate of just 1.37 children per woman. If these trends hold, we may see the family divide become even further entrenched in American politics.