From “Callused Hands: The Shrinking Working Class White Vote” by Keith Gaddie and Kirby Godel at HuffPo:

SO HOW ARE WHITE WORKING CLASS VOTERS DIFFERENT? We used a technique called OLS regression to introduce statistical controls for several white voter features, including party identification, ideology, education, income, age, and sex, so we could isolate the effect of being self-identified white working class, and living in a union household, to compare working class whites to other whites on attitudes towards government, the role of government in the economy, and race issues.
Attitudes Toward Government: Whites in the working class are more distrustful of government than other Americans…Working class whites express greater cynicism toward government than the middle or upper class. However, these differences are not larger now than 40 years ago.
Attitudes Toward Equalitarian Values and Government Spending: A major controversy about working class whites is that they vote against their economic interests because of social issues – ‘what’s the matter with Kansas’ argument popularized by Thomas Frank. Data from ANES show working class white support for government jobs, government spending for services, and equalitarian values are unchanged since before the Reagan Revolution.
Working class whites are more supportive of government guaranteeing jobs and income and, in general, of equalitarian values than other whites. They are not, however, more supportive of government spending on services in general, probably because it is hard to tell what target groups would benefit from this spending.
One way of interpreting these results is to say that self-identified working class whites should be receptive to populist arguments for a more active federal government. But, that support is conditioned on government activity being aimed at improving the wages and employment opportunities available to white working class people.
Racial Attitudes: Does race matter? There has always been a racial subtext to the white working class…The working class whites support for greater economic equality does not translate into support for race-based policies…This primarily reflects differences between working class southern whites and all other whites more generally…
…Our initial look into the political world of working class whites afforded few surprises. We see a political world of the white working class that is less efficacious, less trusting, and finds government less responsive. This world is open to government action on jobs, but not on programmatic poverty spending. It is a world that is skeptical about aid to minorities, especially among southern working class whites.
…Government is an acceptable actor to intervene in the economy if it does so to create employment. But, when government acts to assist through programs or other policies that do not promote employment or wages, the working class reacts with skepticism. And, it is skeptical of assistance to blacks, especially the southern white working class.
These are not surprising findings. But, these results describe a political world where the white working class is increasingly hunkered down. They confront a political environment where they are divided from other whites based on education, economics, and expectations. And, they are divided from working people of color by both different political worldviews but also skepticism regarding how government engages race policies. And, they have become smaller as a political force and have less economic clout and security in this era than at any time in the last 80 years.

If the authors are right, Democrats may be able to increase their share of the white working class vote by emphasizing their support for government action that promotes economic uplift and jobs for all races. Even a small increase in Democratic share of this still-large, though shrinking demographic entity could secure a stable majority for decades.