Politicians and the media generally like to talk about the middle-class.
On the rare occasion that any of them mentions the working class, they always put the word "white" in front of it.
It leaves one with the impression that blacks are a monolithic entity, and thus are single-issue voters. This impression, which does the black community a tremendous disservice, breaks down under close examination.
It turns out that blacks are as interested in kitchen-table issues as whites are.

But in an election where racial rhetoric was so prominent and pointed – and where the first black president exhorted voters to choose Hillary Clinton – Trump’s showing came as a surprise. Among black men, Trump won 13 percent...
“I’d much rather have a guy look me in the eyes and tell me what he really feels than try to tell me what he thinks I want to hear,” he says. “That’s a man whose hand I’ll shake. And that’s why I have no worries about Trump.”
The data don’t point to a “success” for Trump in courting black voters, but they do point to important nuance. For some black working-class men, like Melendez, Trump’s economic rhetoric resonated more than his racial rhetoric. In short, like their white working-class counterparts, they saw in Trump the man who would bring back their jobs and their dignity.

This should be surprising to no one except for white liberals.
A far higher percentage of African Americans than whites are working class, and have been historically.
Black American wealth was absolutely crushed over the past decade. If current trends continue, median wealth for black Americans will fall to $0 by 2053. That's a crisis by any definition. A crisis that liberal Democrats like to put into a non-economic context.

There is a political cost for ignoring this crisis.

Eighty-four percent of the 582 working-class African-American voters in central Ohio that were interviewed by Working America say they disapprove of Trump’s job performance. And 26 percent have engaged in a political action since Trump was elected. That’s a higher proportion than Working America found among white Clinton voters when they surveyed swing voters in central Ohio in March. But of the black voters surveyed only 33.9 percent said they were familiar with the term “resistance.”...
Given all that was at stake, why did black turnout for 2016 election drop 10 percentage points to 61.8 percent in Ohio? Working America canvassers found that the people they interviewed were suffering economically and did not think the government would help them, or that having a Democratic president would make a difference.

The attitude of the Democratic establishment is that black America is all about racial issues, and economic issues won't resonate with the black community. That's why Bernie Sanders' focus on economic issues will fail to attract black voters.
Recent polls have shattered that myth.

The lack of nuance that white liberals have in viewing the black community can be seen in the issue of immigration.

Measures of economic self-interest more strongly account [than estimated collective-interest] for the opinion of African American members of the working class when compared to their middle-class brethren … [and] it appears that class membership is a more powerful force in shaping the attitudes of Blacks in comparison to Whites …

For African Americans who lost a job to an immigrant, working-class membership resulted in a 13 percentage point increase in the probability of support for an increased federal role in workplace oversight [against employment of illegal immigrants] when compared to middle-class African Americans who experienced a similar loss.

Working-class African Americans are significantly more supportive of policies that seek to: decrease the number of immigrants coming to the United States, increase the federal role in verifying the employment status of immigrants, and attempts to amend the Constitution’s citizenship provisions.

This is the danger of the Democrats' full-embrace of immigration.
They lightly disregard the white working-class rejection of open immigration as they are all racists.
But how does that work with the black working-class rejection of open immigration?
How does that work with the historic rejection of open immigration by the black working-class?
It doesn't make sense on a skin color spectrum. It only makes sense on a class-based spectrum.