I recently read a great working paper titled “Bound by Blackness: Understanding the Maintenance of Black Democratic Party Loyalty” by Laird et al. that sheds important new light on the partisanship of African-Americans. The persistently strong attachment to the Democratic Party among blacks has long been explained as a function of “linked fate” (concern among blacks with what happens to blacks as a group). However, after showing the weak evidence for this theory, these authors use several pieces of evidence to argue for a different theory that center on social sanctions leading blacks to overwhelmingly identify as Democrat. Namely, pressure from group expectations leads to greater compliance with the group norm that is Democratic support among blacks. Some of these same authors offer compelling evidence for this same theory in other research as well.
I thought one natural (and simple) extension of this work would be to check how black political identity varies by local social context. With its large sample of blacks (7,920) and geographic codes (county FIPS and zip code) that could link to social context demographic data from the Census, the 2016 CCES provides a good opportunity to see whether black political identity varies by the extent to which they live near other blacks. In this way, while far from perfect, I could capture a similar mechanism of pressure to comply with group norms driven by the amount of surrounding group members who could influence an individual. My general expectation is thus that blacks should have greater attachment to the Democratic Party in areas that contain more blacks.
In the above plot, I generally find support for this expectation. The x-axis shows 10 intervals representing the percentage of blacks living in black survey respondents’ zip codes, and the y-axis shows the percentage of black survey respondents that identify as Democrat (Democrats + Democrat leaners). In zip codes that range from 0 to 10 percent black, blacks identify as Democrat 74.1 percent of the time. At the highest level of living with co-racial individuals–in the 90-100 percent black zip code range–blacks identify as Democrat at a 89.8 percent rate. Thus, if the social sanctions theory applies here, blacks receive the least amount of group pressure to comply with norms (i.e. Democrat support) in the areas with least amount of fellows blacks (0-10 percent) and that translates into the lowest level of Democratic attachment across all zip code ranges. In a local context where blacks live with many other blacks (90-100 percent), blacks identify as Democrat at the highest rate across all zip code ranges, perhaps because of greater pressure to comply with group norms as part of living around more co-racial individuals. (Note: the proportions at 90-100 and 80-90 are statistically significantly different at conventional levels, but the 90-100 and 30-40 proportions are only different at p<0.10.)
Interestingly, black Democratic attachment does not monotonically increase as percentage black zip code increases. Instead, there’s a peak at the 30-40 percentage range, after which Democratic attachment decreases and then picks up again around the 80-90 and then 90-100 range. The relationship therefore doesn’t perfectly follow my expectation, and so the evidence here is not extremely strong. However, the Democratic identification estimates at the highest and lowest levels of black zip code percentage ranges is telling, and suggest there is some type of context effect that shapes the extent to which blacks support the Democratic Party. In this sense, the results here lend some additional support for the theory of social sanctions and group compliance pressures as an explanation for black partisan homogeneity.
Update 3/22/18:
I plotted the same relationship from the last graph but broke it up by self-described (five-point) ideology below. Interestingly, the relationship between amount of co-racial individuals and attachment to the Democratic Party appears stronger among the two conservative groups (“conservative” and “very conservative”) than among the other ideological groups. As with the overall relationship, this specific result mirrors another one of the findings from Laird et al.’s work: conservative blacks experience this social pressure to conform to group expectations (based on their social context) the most.
Agadjanian Politics 