Racial resentment against African-Americans across all party-political lines corresponded with higher support for voter ID laws, according to one study at the Centre for Political Communication at the University of Delaware, of attitudes among non-African Americans.
Correlation between racial resentment and support for Voter ID across all party-political lines
For every sample sub-group, including Republicans, Conservatives and Democrats, support for voter ID was higher among people who expressed higher racial resentment against African Americans, than among groups who expressed lower resentment.
Republicans showed the highest support for voter ID laws, compared to Democrats and Independents; they also showed the highest resentment against African Americans, compared to Democrats and Independents. Given a total sample size of 906 people, the study was unable to say much of statistical significance about views on Voter ID within the small sub-group comprising of Republicans who expressed little or no racial resentment against African Americans. However, no mechanism was suggested that would support diversion from the trend in the sample as a whole, within which racial resentment against African Americans correlates with support for Voter ID; and the sample data is consistent with the hypothesis that higher racial resentment corresponds with support for voter ID among Republicans, just as it does among other groups, inclusing Democrats.
The study reports:
The link between “racial resentment” and support for such laws persists even after controlling for the effects of partisanship, ideology, and a range of demographic variables.
So, for example, among Republicans, those few with lower racial resentment against African Americans, had 87% support for voter ID laws. Whereas among those Republicans who expressed higher resentment against African Americans, the support for voter ID laws was 93%. Within Democrats, both the levels of racial resentment and the levels of support for voter ID were lower: 47% of Democrats with low racial resentment supported voter ID; 77% of Democrats with high racial resentment supported voter ID. Overall, Democrats scored just 0.32 on the racial resentment scale (0.0 would be least resentment, 1.0 would be most), whereas Republicans scored 0.54
Problems with sub-group sample sizes
NB the error margin in the whole sample is 3.9%
So the sample consisted of too few Republicans with low racial resentment, to be able to say much (with statistical significance) about their views on voter ID, relative to Republicans with high racial resentment. The study does not give any explanation about why it was hard to find enough Republicans who expressed little-to-no racial resentment. All we know from the report of the survey is that racial resentment against African Americans was higher within Republicans than within any other group. By comparison, the lower support for voter ID within Democrats, and the lower racial resentment, means that there are higher sub-group samples within each of the four quadrants of: support for voter ID yes/no plotted against racial resentment high/low.
In summary
From the University's report of the survey:
Brewer, the center’s associate director for research, said, “These findings suggest that Americans’ attitudes about race play an important role in driving their views on voter ID laws.”
(my emphasis)
Closing thoughts on correlations
Note that this is a study of correlation and corresponding attitudes: not of reasons why people support voter ID or not.