Public and political concerns that demographic changes being driven by migration have been overly rapid may underlie much of the increasingly fractious debates about migration policies. Humanitarian and egalitarian sensibilities often underlie individual and institutional support for expanding international migration into Organization for Economic Co-operation and Development (OECD) countries. Other conceptual ambiguities prevail as to whether SoS conflicts can arise in the most prosperous countries of the modern world, such as the 34 member states of the OECD. The content and passion of contentions about immigration and refugee policies in OECD countries make clear that they must also be discussed in terms of their political and electoral implications. From the 1960s until about the turn of the century, United States immigration policy had been a largely bipartisan issue, with continuation of expansive immigration politics attracting substantial support from both Democratic and Republican parties.