Growing polarization among the US electorate has in recent years attracted considerable attention from academic and non-academic observers. This paper examines some of the ways in which polarization affects US foreign and security policy in the post-Trump era. In particular, the paper offers an account of why bipartisan agreement over the so-called “rise of China” has prevailed in the face of powerful trends towards increased polarization, while domestic opinions over US aid to Ukraine have become much more contested. Drawing on a constructivist understanding of foreign policy as performative of a certain vision of the domestic self, this paper shows how US aid to Ukraine has become entangled with competing visions of the US, while domestic opinions of China have remained stable. While such a constructivist understanding does not necessarily challenge rationalist accounts, it is helpful in unravelling the link between national identity, domestic polarization, and foreign policy.