Political leanings might determine more than how people vote. This study, co-authored by Christina Gibson-Davis, explores the link between political identity and young adults' fertility desires from 1989 to 2019. Using data from a survey of 12th graders, it finds that Republicans consistently desired more children than Democrats, with the gap widening over time. Initially, differences in religiosity and gender attitudes explained these gaps, but from 2004 onwards, these factors only partially accounted for them. By 2014, Republicans had a higher likelihood of wanting more children and a lower likelihood of avoiding parenthood, a trend that continued through 2019. The study concludes that political identity has increasingly influenced fertility desires.