Bruce Cain, a political scientist at Stanford, agrees with Lupia in many respects, but places greater emphasis on economic policy as a coalition building mechanism:

The problem is both substantive and cultural, and hence the Democratic response has to be on two levels. Substantively, the party needs to develop a stronger program regarding the job opportunities and economic prospects of these angry white voters. If all the jobs and money are on the coasts, and the industries that used to support workers are increasingly automated and subject to complex trading across NAFTA countries, then we need to make sure that US workers have the skills to participate in that economy. We made only halfhearted efforts with respect to NAFTA and when they did not work well because workers did not want to move from their communities or because the job skills they got were not adequate, the party moved on.

Cain is critical of the lack of attention Democrats paid to economic issues in 2016:

Hillary taking support behind the blue curtain for granted is symptomatic of the party’s shift to middle and upper middle class professional and creative class workers. The party needs to offer policies that assist them, and it has to be something that moves forward towards engaging the new economy, not retreating to the past a la Trump.

In Cain’s view, the lack of focus on the economic needs of the heartland is of a piece with the sociocultural remoteness of Democratic elites:

The cultural problem is Democrats looking down their noses at blue collar work and flyover country. First, cut that shit out. Second, let’s get back to celebrating the work of those who fix pipes, install wind farms, etc. Many of us in Democrat bubble lands are just too full of ourselves. Also, let’s look at how to upgrade vocational schools and training to make it more prestigious, not places where people are relegated to because they cannot compete in a college prep curriculum.

Paul Begala, a Democratic consultant and adviser to Bill Clinton, also comes back to the cultural breach between upscale Democrats and the white working class and poses this basic question:

If you look at the Democratic platform, or Hillary’s speeches on the economy, Democrats have a raft of good ideas, loads of sound policies that would make life better for the white working class. So why have they rejected us?

White working-class Americans are “dying before their time,” Begala wrote in an email, specifically citing the rise in alcoholism, cirrhosis, drug addiction, overdoses, suicide and poisoning:

If the life expectancy of, say, Somali immigrants in Minnesota suddenly took a dive, Democrats would be falling all over each other trying to ascertain the causes and advocate the cures. We owe white working-class Americans no less.

Begala stresses that Democrats must show respect for the culture of the white working class:

As a straight, white, married, gun-owning, church-going man, many of my hunting buddies feel like Democrats have contempt for them.

Begala’s views are shared by Sosnik, who emailed me along the same lines:

More than any set of issues, the first thing that we Democrats need to do is to deal with the perception that the party is controlled by elites on the coasts who look down on the rest of the country. If we cannot overcome that core disconnect, we will never have a chance at getting their vote. That was part of Bill Clinton’s success as a politician.

Nathaniel Persily, a professor of law and political science at Stanford, makes the point succinctly, focusing on the importance of candidate recruitment: “How can the party nominate someone, or be led by someone, like Bill Clinton, rather than Hillary Clinton?”

Danielle Thomsen, a professor of political science at Syracuse University, recognizes how difficult it will be for Democrats to make inroads into Trump country. She also focuses on the importance of candidate recruitment and candidate quality. Thomsen emailed:

Because the Democratic Party has been moving steadily to the left in recent decades, it will be hard for them to simultaneously appeal to the ideologically liberal base that has been created along with this shift and to white middle Americans who view their interests to be in direct conflict with some of those who make up the liberal bloc of the Democratic coalition.

One approach to “getting Middle America to identify with and see themselves as partners alongside racial and ethnic minorities, environmentalists, feminists, young Americans, secular Americans, and other groups who are squarely in the Democratic coalition,” she suggests, would be a concerted effort to recruit “candidates who represent the slice of middle and working class Americans whose lead they could follow and rally behind.”

There are some observers who are quite pessimistic about the ability of the Democratic Party to expand its base. Ryan Enos, a professor of government at Harvard, emailed me:

In the short run, there is little they can do. The disconnect between Democrats and rust-belt working-class whites is not about any recent Democratic candidate or particular policy, but about fundamental features of human psychology reacting to large-scale economic and social change. The rightward political shift by rust-belt whites fits a long pattern of backlash politics that happens when places diversify. The backlash that moves voters to the right is amplified when people feel economically and socially insecure, so the ingredients in the rust belt are perfect to pull voters into the Republican Party.

In theory, Democrats could shift to the right to appeal to these white voters, but, Enos points out, party leaders

are not going to abandon their ideological commitment to immigration and racial equality and they are not going to abandon the nonwhite voters who are a significant part of their constituency.

In this context, according to Enos,

the best they can currently do is do a better job of mobilizing nonwhite voters in these states and the white voters they still have. There is something to be said for the strategy of nominating a presidential candidate that connects with these voters, perhaps even a nonwhite candidate who mobilizes the Obama coalition.

With polarization driving differences over race, ethnicity and cultural values to new heights, the capacity on the left for the kind of full-fledged empathy for working class Trump supporters described by Sosnik and Begala is at a low point. Indeed, Shanto Iyengar and Sean Westwood, political scientists at Stanford and Dartmouth, found in a 2015 paper that partisan identity is now more polarized even than racial identity.