US policy toward immigrants, and in particular ones from Mexico, revolves around key symbolic formations about the US-Mexico border, as materialized in massive policing of and wall-building at that border. Kitty Calavita (1990) importantly ﬁ rst suggested the symbolic politics analysis of immigration policy, and I extended it to border policing in my work of the 1990s (Heyman 1999a, 1998, 1995). Disturbingly, these ideas have only become more relevant and extreme over time; as I write in 2010, over twelve hundred US troops are being sent to this peaceful border (that is, peaceful on the US side, where the military units are being deployed) (Mendoza 2010). Why and how does this occur? This chapter examines the core idea that the US-Mexico border can be perfectly controlled and sealed off from all harm. It locates this idea in the historical and contemporary dynamics of race and citizenship, attending to those phenomena in the context of ideologies, politics, and economics of the United States in its relationship to Mexican working people. Taking a political-economy perspective, but not one a reductive one, I explore how transnational migration through the US-Mexico border manifests profound contradictions emerging from capitalism seen as a fully socio-cultural phenomenon, including but also extending beyond obvious economic interests.