I know this question has been asked by bloggers before, but now even Vanity Fair is asking if the Dems want to lose in 2020.

Some names, like Gillibrand and Harris, may have some promise. But the rest may as well have been grown in a lab by Republican scientists in order to guarantee a Democratic defeat.

The Dems problem goes far beyond potential 2020 candidates, which are increasingly made up of billionaires.

It recently occurred to me that both political parties primarily exist to do harm to their own voting base.
Republican policies target their own voters for economic destruction, while Democrats lead to charge for deregulation and FTAs, thus crippling the working class they pretend to represent.
This makes the political partisans the most masochistic people out there.

While Republicans have a ready-made scapegoat in Trump for when things go wrong, and they most certainly will, the Democratic establishment appear single-minded in a quest of self-destruction.

Like Inspector Javert or, perhaps more appropriately, Wile E. Coyote, the Democrats remain fixated on getting their man, Trump, and proving wrong the voters who elected him. At first glance, the daily drip of new and shocking revelations over Russia looks like a mounting shadow over the White House, and it very well may prove to be its undoing. But the instant scandal—it seemed to start the minute Trump was declared president-elect—also threatens to further decimate the Democratic Party. And Democrats don’t seem to know it.
To those with a bit of distance from cable news—that is, every sane person in America—Democrats seem to be replaying the exact strategy that lost them the last election. What, pray tell, is the Democratic Party’s message otherwise? That they don’t like Russia, except when they did? That they believe Russia is the biggest national security threat to America, except when it wasn’t? Democrats appear to have spent about two minutes trying to figure out why the voters of Wisconsin, Ohio, Michigan, Pennsylvania and, very nearly, Minnesota rejected them only a few months ago.
...What did the Democrats do to rebuild the faith and trust of the “forgotten” voters they still seem to have trouble remembering? They doubled down.

Since the election defeat, Democrats are dropping in the polls and an overwhelming majority of the public thinks the Dems are out-of-touch.
Are the Dems responding to these alarming trends by creating an actual governing agenda that would give the struggling working class a reason to vote Democratic? Nope.
It's all "Scary Trump!" all the time. As if President Pence would be a significant improvement.
Why don't the Dems appeal to the working class with an agenda to meet their needs? Because that would conflict with the real Democratic base - comfortable suburbanites.

Pitching one's campaign at anxious white suburbanites with catastrophically mistaken notions about government financing rules out actually fixing most of the crises facing the country. It means running on fiddly little tax credits and pointlessly means-tested small-bore programs, just like Hillary Clinton did.
...As famed Democratic pollster Stan Greenberg argues, Democrats have a working-class problem — of all races, not just whites.

Both parties have completely abandoned the economic concerns of the working class, but a case can be made that only Republicans care about the working class' cultural concerns.
The Democrats cultural agenda increasingly matches the cultural interests of the affluent.

This affluent base can embrace the progressives’ social agenda — meeting the demands of feminists, gays and minority activists. But they are less enthusiastic about the social democratic income redistribution proposed by Bernie Sanders, who is now, by some measurements, the nation’s most popular political figure. This new putative ruling class, notes author Michael Lind, sees its rise, and the decline of the rest, not as a reflection of social inequity, but rather their meritocratic virtue. Only racism, homophobia or misogyny — in other words, the sins of the “deplorables” — matter.
The Washington Post, owned by Jeff Bezos, the world’s third-richest man, reflects this socially liberal, but oligopolistic, worldview. Last spring, Bezos worked assiduously to undermine Sanders’ campaign, then promoted Clinton, and now has become a leading voice in the anti-Trump “resistance.” The gentry wing of the party, which dominates fundraising and media, as the opposition to Sanders reveals, likes its money. The tech community is famously adept at avoiding taxes.

The Dems like to richsplain to the working class peasants because that's how their wealthy donors think.
Whether they honestly believe that minorities don't put much importance on economic issues is neither here nor there.

“The importance of jobs is consistent with what we’ve been seeing for a long time as the most important problem across the board – ethnicity isn’t that relevant," Lonna Rae Atkeson, a professor of political science at the University of New Mexico, told Fox News Latino.
"The thing about the economy for everyone, it’s a doorstep issue. You walk outside, and you can see what’s happening to people and see how it affects you,” she said.

It's in the interests of the elite that us working class peasants continue to focus on our superficial differences, rather pay attention to the other 99% of our lives that we have in common, such as getting a job and paying the bills.

When it comes to ethnicity, African Americans were much more likely (50%) to be concerned about economy/jobs compared to whites (29%), Hispanics (34%) and Asians (45%).