Gini and the Politicization of Immigration
These three graphs explore the relationship between the Gini coefficient for economic inequality (World Bank data) and the politicization of immigration. The politicization of immigration is measured from political claims in newspapers (data from http://www.som-project.eu/), and a distinction is drawn between salience (more claims about immigration) and polarization (positions of claims differ more).
This analysis was a wide shot to begin with. Solt (2011, Journal of Politics 73(3):821-30) showed that nationalism is associated with economic inequality: more inequality prompts more nationalism ("diversion"). It is conceivable that this can be expanded to the politicization of immigration, which might be linked to nationalism. The figures (simple scatter plots) suggest that this is not the case.