This chapter tracks the period after 1985, a time when party polarization transformed both presidential appointments to the Supreme Court and the elite social networks that the Justices were a part of. Starting with the 2010 appointment of Democrat Elena Kagan to fill the seat of liberal Republican John Paul Stevens, the Court’s ideological divide is also a partisan divide. This chapter explains the circumstances that propelled today’s partisan divide—circumstances that make it likely that the divide will persist. In particular, ideology is now a dominant feature of judicial nominations. Correspondingly, the conservative legal network and, with it, the Federalist Society plays a critical role in all aspects of the nomination process for Republican presidents. Once a conservative Republican joins the Court, moreover, the Federalist Society reinforces his or her conservativism through social interactions, speaking engagements, and much more. For their part, Democratic Justices are part of left-leaning social and political networks.