Beyond identity politics: to reach the white working class, promise an economy that "works for everyone.".

• Author: Teixeira, Ruy

In the last three presidential elections, the Democratic candidate lost among white working-class (non-college-educated) voters by an average of 22 points. The worst performance came in 2012, when Obama lost this group-once the bulwark of the Democratic coalition--by a staggering 26 points (62 to 36 percent).

The loss of this key demographic is mitigated to some degree by its shrinking size. The numbers of white working-class voters will probably dip to just 30 percent of all voters by 2020 and 44 percent of white voters. This is a dramatic decline from 1988, when white working-class voters were 54 percent of all voters and almost two-thirds (64 percent) of white voters.

Some observers argue that since the ranks of the white working class are declining, Democrats should simply rely instead on their rising "Obama coalition" of minorities, unmarried and working women, seculars, Millennials, and educated whites living in more urbanized states. Yet it would be a grave mistake for Democrats to count on this strategy.

For one, the Democrats' deficit with working-class whites was the key reason for the GOP landslide in 2010, and could hand the Republicans another big win in the upcoming midterm elections. Despite their declining numbers, white working-class voters will be an ever-present threat to progressives in elections and to progressive governance as long as so many remain so hostile to the party.

The Democrats don't need a majority of white working-class voters to come over to their side. But they do need to deny the Republican Party the supermajorities of white working-class voters that Republicans successfully mobilize today. Moreover, broadening the Democratic appeal to white working-class voters should greatly reduce the threat posed to the party when other constituencies, such as Latinos or younger voters, exhibit only modest turnout--particularly a problem during off-year elections--or waiver in their support for Democrats. Furthermore--and this is critical--by depriving the GOP of its uncontested supermajorities among white working-class voters, Democrats would finally force today's intransigent Republican Party toward the center. It is only those supermajorities that allow Republicans to thumb their noses at the rising Obama coalition and dig in their heels at the smallest progressive change.

Take that advantage away, and the electoral arithmetic becomes so dire for Republicans that their strategy will have to change simply to remain competitive. True, a more moderate and reasonable GOP would attract more voters who now vote Democratic, but overall it would be a plus for progressive governance by improving the climate for legislation that actually addresses social problems.

Is there reasonable hope that such a coalition can be formed? We believe there is.

Start with the evolution of the white working class itself. Over time, we expect that generational change will make the white working class more liberal and open to progressive agendas...