Racial Diversity, Electoral Preferences, and the Supply of Policy: The Great Migration and Civil Rights

Abstract

How does the racial composition of local constituencies affect voters preferences and politicians behavior? We study the effects of one of the largest episodes of internal migration in US history, the 1940-1970 Great Migration of African Americans, on both demand for racial equality and supply of civil rights legislation. We predict black inflows by interacting historical settlements of southern born blacks across northern counties with differential emigration rates from different southern states after 1940. We find that black in-migration increased support for the Democratic Party and encouraged grassroots activism. Data on pro-civil rights demonstrations and historical surveys reveal that segments of the white electorate, such as Democrats and union members, supported blacks struggle for racial equality. At the same time, backlash against civil rights erupted among Republicans and whites more exposed to racial mixing of their neighborhoods. Mirroring the responses of the electorate, Congress members representing areas more exposed to black in-migration became more supportive of civil rights legislation. Such average effects, however, mask substantial heterogeneity, as Democratic and Republican legislators became, respectively, more liberal and more conservative on racial issues. Taken together, our findings suggest that, under certain conditions, cross-race coalitions can emerge, but also that changes in the composition of the electorate can polarize both voters and politicians.