(Ben Margot/AP)

When a party loses as catastrophically as the Democrats lost Tuesday, something very big has gone very wrong. Democrats can’t blame the blowout simply on the six-year itch, or low midterm turnout, or Republican negativity, or Barack Obama’s too-cool-for-rule presidency. What fundamentally ails the Democrats, rather, is the same ailment that afflicts incumbent parties throughout the advanced economies, and parties of the center-left in particular: their inability to deliver broadly shared prosperity as they used to do.

The Ebola and Islamic State phobias certainly didn’t help, but the overwhelming anxiety that the Democrats failed to address was the economy. In national exit polls, 45 percent of respondents cited the economy as their chief concern — way ahead of health care, which ranked second at 25 percent, not to mention foreign policy, which clocked in at 13 percent.

Dig a little deeper into the public’s economic fears, though, and you might conclude that the Democrats should have had a good election night. Sixty-three percent of respondents told pollsters they believed that the U.S. economic system generally favors the wealthy, while just 32 percent said that it is fair to most. And a wave of ballot measures to raise state or city minimum wages carried wherever they were put before voters — from deepest-blue San Francisco and Oakland to solid-red Nebraska, South Dakota, Arkansas and Alaska.

Yet Democrats were singularly unable to take advantage of such unarguably populist sentiments. Never mind their failure to win in red states or hold the Senate. They failed to turn out their voters, or persuade the hitherto persuadable, in such blue bastions as Maryland, Massachusetts and Illinois, where they lost governors’ races. Even in the people’s republic of Vermont, the incumbent Democratic governor won so narrowly that the race will be tossed to the legislature (as Vermont law requires when no gubernatorial candidate breaks 50 percent). If current margins hold, there will be just 18 Democratic governors in January, and just eight in the 31 states that don’t border the Atlantic or Pacific.

Tuesday’s verdict makes clear that the Democrats cannot win by demographics alone. Republicans failed to improve their dismal performance among Latino and African American voters or among the young, but these groups’ low turnout helped doom Democrats in blue states particularly. Voters ages 18 to 29 constituted just 13 percent of the electorate, down from 19 percent in 2012. Latinos favored Democrats by 62 percent to 36 percent, but they constituted just 8 percent of voters, the same level as in 2010, despite their growing share of the population. Tuesday’s electorate tilted white and old — which is to say, Republican.

Yet the same factors that lowered the turnout of the Democratic base also cost the party votes among whites: the failure of government to remedy, or even address, the downward mobility of most Americans. Democrats who touted the nation’s economic growth did so at their own peril: When 95 percent of the income growth since the recession ended goes to the wealthiest 1 percent, as economist Emmanuel Saez has documented, voters view reports of a recovery as they would news from a distant land. Even though it was the Republicans who blocked Democrats’ efforts to raise the federal minimum wage or authorize job-generating infrastructure projects or diminish student debt, it was Democrats — the party generally perceived as controlling the government — who paid the price for that government’s failure to act.

But with the exception of Sen. Elizabeth Warren (D-Mass.), who has been plenty outspoken about diminishing the power of Wall Street, the Democrats have had precious little to say about how to re-create the kind of widely shared prosperity that emerged from the New Deal. The regulated and more equitable capitalism of the mid-20th century has morphed into a far harsher system, just as Americans told the exit pollsters, and the Democrats, whose calling card to generations of voters was their ability to foster good economies, are at a loss for how to proceed. Like their counterparts in the center-left parties of Europe, they had crafted national policies that bolstered the power and income of the majority of their citizens. But globalization, technology, financialization and the erosion of workers’ power have undermined those policies and fractured their electorates.

Democrats can’t rely simply on their demographic advantages and their edge on cultural issues to win the White House in 2016, much less retake Congress. They need to go where they haven’t gone before — increasing workers’ power and incomes within corporations, say — if they are to create an economic platform credible enough to win back the country.

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