In short:

[T]he racially tinged ads now running in Ohio, Colorado and other battleground states may succeed in influencing racially resentful white voters, but if so, the people they influence are more likely to be educated than not. Consequently, this is less likely to translate into more Republican votes, for two reasons. First, on average, educated whites are more racially tolerant than non-college-educated whites. Since racial tolerance diminishes support for candidates who appear to make racial appeals, politicizing the racial attitudes of these voters is unlikely to be an effective strategy. Second, educated voters hold stronger partisan attachments than less educated voters. By the time they see campaign advertisements, they are more likely to have made up their minds about which candidate to support, and they will not be easily budged.