In this, the pre-primary 2016 presidential race season, it's clear that Democrats plan to make economic health and inequality a major theme of the campaign.

The Elizabeth Warren movement has forced all Democrats to talk in these terms. And indeed, Hillary Rodham Clinton, Bernie Sanders and Martin O'Malley have all begun talking about these issues on the campaign trail and sharing policy ideas. All of those campaigns have made hay of GOP presidential contender Jeb Bush's apparent suggestion that people need to work more hours (Bush says he was referring only to part-time employees). Democrats also are going after Republicans for opposing a minimum-wage increase and are hitting them on other policies they say exacerbate the wage gap.

But where are these issues the most acute? A new study has identified 10 large cities where the most substantial shares of the population live in economically distressed communities. It also shines a spotlight on the major and midsize cities where the gaps between those struggling and those doing well have grown largest.

And some of the cities might surprise you. There are big problems in red states as well as blue. But although many of the most-distressed cities are in blue states, a majority of the most unequal cities are in red states.

The study is from the Economic Innovation Group, a new bipartisan think tank that aims to harness private money and business solutions to address some of the country's biggest economic challenges.

Here's a look at the big cities where the largest volume of people are living in economically distressed communities.

Quick translation of the map above: In these cities, a lot of people are struggling. In some, an overwhelming majority.

And here's a map of the big and midsize cities in which the people who are struggling the most also happen to live in close proximity -- in the same city -- with those who are doing well. Call them the most unequal cities.

A few cities on these maps are in places from which 2016 GOP contenders hail -- and hence could be focal points for Democratic attacks. Former Texas governor Rick Perry has touted the job creation that occurred in Texas on his watch; these maps suggest that progress didn't reach everyone. And before he was Wisconsin governor, Scott Walker was a Milwaukee County executive. Both Texas and Wisconsin have bucked a national trend toward boosting the state's minimum wage.

John Lettieri, the Economic Innovation Group's co-founder and senior policy director, and Steve Glickman, a co-founder and the group's executive director, said they wanted to get a sense of why so many Americans seem to think they are living in ongoing times of economic challenge. To do this, they thought they needed something more than unemployment figures.

The group's researchers created an index of economic distress and inequality based on seven metrics. That list includes: the share of people age 25 or older who have a college degree, the portion of the city's livable housing stock that's vacant, the unemployment rate and changes in the labor-force participation rate, the percentage of the population that lives on incomes below the federal poverty line, how a Zip code's median income compares to that same figure statewide and what share of the area's businesses have closed. In each of those categories, the index relies on Zip-code level, five-year averages of census data to account for one-time big events and economic flukes.

"If you are sitting in a place like New York, D.C. or L.A., you probably have the sense that the recession is over," said Glickman, a Democrat and former senior economic adviser in the Obama White House. "That was terrible, but we've come out of it now. But the recession really changed so much about local economies -- some much more than others."

But there are also things that weren't included in the index that Glickman and Lettieri, a Republican who among other things worked as an aid to Sen. Chuck Hagel (R-Neb.), think matter nationwide. These are phenomena shaping the entire economy, everywhere.

During the recession, many community banks closed or failed. These banks have long been a major source of funding for small businesses. And a full 75 percent of venture capital -- the pools of private investor money that helped make companies such as Facebook and Google what they are -- goes to companies in just three states, Glickman said. You can probably guess them, but here they are: California, Massachusetts and New York. (The National Venture Capital Association's data backs that up.) To make matters worse, the country's total number of businesses has been in a state of decline for the past 30 years.

And it's on those last three points that the Economic Innovation Group wants to focus attention. Most startups fail. But new businesses generally create jobs while large and existing ones tend to shed them, Glickman said. And, of course, the personal economic gains that come with a job also bleed out into your community.

For those who think that this analysis drives to a place a little too far, Lettieri offered this: For most Americans, the vast majority of their wealth -- money and other assets after accounting for debts -- is tied up in the value of their home.

"So, if your home is underwater," Lettieri told me, "community banks are gone and venture capital won't lend or doesn't really look at investment opportunities in your state, well how could you fund a business?"


Here’s how the Distressed Communities Index averaged the seven economic indicators. For each indicator, all Zip codes (with at least 500 residents) were given a 1-100 percentile ranking based on how they compared to other Zip codes on each economic measure. For instance, a Zip code’s educational ranking was 75 if the share of high school graduates was greater than 74 percent of other Zip codes. Percentile rankings for all seven indicators were calculated, and a simple average was used to calculate the overall index value for a Zip code. Values for cities, counties, states and congressional districts were calculated using the percentage of residents who live in distressed Zip codes.