Republicans concluded long ago that granting a path to citizenship to the undocumented would hurt their electoral prospects dramatically. A widely publicized report published in 2001 by the Center for Immigration Studies noted that “high levels of immigration have been a boon for Democrats” since, once naturalized, Latino immigrants “add significant numbers to the Democratic base in the major immigrant-receiving states.” The report suggested that even if Republicans cultivate their loyalty by voting in favor of an amnesty, these immigrants are likely to read it only as a mixed signal: “Once naturalized and mobilized, these voters will be almost certain Democratic constituents, regardless of how Republicans vote on amnesty.”
Following this line of analysis -- and catering as well to strong anti-immigrant views among base conservative voters -- GOP leaders have pursued a dual strategy. First, at the national level, they have pushed in Congress for enforcement-only immigration policies that have the goal of reducing the numbers of immigrants that arrive into the country as well as the numbers of those that are already here. This has been done by devoting more resources to protecting the border, and by forcing the Federal government to implement more stringent deportation policies (an area in which the Obama administration has proved to be very effective). Second, at the sub-national level, Republican leaders have passed laws and ordinances aimed at making life for undocumented immigrants so difficult that they will deport themselves. These policies, whose most prominent intellectual author is Kansas Secretary of State Kris Kobach, are known as "attrition through enforcement."