President Trump speaks at a rally Saturday in Michigan. (Rena Laverty/EPA-EFE/Shutterstock)
Contributing columnist

Ronald A. Klain, a Post contributing columnist, served as a senior White House aide to Presidents Barack Obama and Bill Clinton and was a senior adviser to Hillary Clinton’s 2016 campaign.

There are many divisions among today’s Democrats: left vs. center, activist vs. establishment, protectionist vs. free trader. But the most interesting divide is over how Democrats should relate to white working-class voters who supported President Trump in 2016.

Some Democrats, believing that the party lacked a compelling economic plan in the last election, say that they should build a bridge to these voters with a new, populist economic appeal. Others, believing that white working-class voters who backed Trump did so largely because of racial resentment, see such outreach as futile at best — and at worst a betrayal of minority, LGBT and immigrant voters (and their allies) who are the party’s core.

A study out last week from University of Pennsylvania political scientist Diana C. Mutz has been touted by adherents of the latter view. Mutz looked at how voter preferences shifted from 2012 to 2016 to convincingly demonstrate that “issues that threaten white Americans’ sense of dominant group status,” and not a “change in financial well being,” were the driver in white working-class voters backing Trump. The study confirms earlier work showing that many white voters backed Trump due to a view of “white vulnerability,” defined as “the perception that whites, through no fault of their own, are losing ground to other groups.”

These findings may resolve the debate over what happened two years ago. But they don’t tell us what the party should do about outreach to these white working-class voters now and beyond. Is America divided, hopelessly, into two tribes? If so, are campaigns no longer about persuasion and policy — but only exercises in getting more tribe members to the polls than the other side can muster?

As a pragmatist, I find such a strategy unwise. As a policy wonk, I find the idea that ideas don’t matter unpalatable. And as an idealist, I’m not ready to give up on reversing the tribal drift.

Pragmatically, Democrats need to capture a larger share of white working-class voters. Yes, the party can win the national popular vote without them — and thanks to demographic trends, the Democratic base will continue to grow. But the electoral college remains a reality in presidential politics, and as 2000 and 2016 proved, winning the popular vote alone is not sufficient.

Moreover, for Democrats, it is not enough to win elections: To legislate, you need control of the Senate, where power is concentrated in less populous states, and a solid majority in the gerrymandered House. Thus, to achieve real change, progressives need majorities in a wide swath of the country.

From a policy perspective, if Presidents Franklin Delano Roosevelt, Bill Clinton and Barack Obama could build inclusive coalitions to advance progressive aims, than surely future Democratic leaders can, too. FDR’s Social Security, Clinton’s earned-income tax credits for poor workers and Obama’s health-care reform were all examples of policy ideas that crossed “tribal lines” behind progressive goals.

One concept central to these successes was linking progressive aims to the widely shared value of work: tightening the bond between hard work and decent pay, health security and a safe retirement. This may explain why some ideas that Democrats advocated in 2016 — such as “free college” — did not resonate with white working-class voters: Even if such policies were in their economic interest, these voters rejected “free anything” as “handouts.” As Mutz put it, as counterintuitive as it might be, Trump’s “supporters largely oppose strengthening the safety net for those left behind.”

But other progressive policies could bridge that gap. Although a universal basic income might be a step in the wrong direction (as it feeds the resentment of “handouts”), new proposals from Sens. Cory Booker (D-N.J.), Elizabeth Warren (D-Mass.) and Kamala D. Harris (D-Calif).; Sen. Kirsten Gillibrand (D-N.Y.); and Sen. Bernie Sanders (I-Vt.) — to provide a job for any American willing to work — could be on target. This idea would unite voters who want to help people left behind with those who share former vice president Joe Biden’s view that an earned paycheck is central to Americans’ dignity. And it would provide a powerful rebuttal to cruel new GOP plans to take away health-care coverage and other benefits with “work requirements” that would punish the disadvantaged for not having jobs that don’t exist.

Finally, the alternative — giving up on outreach to these white working-class voters — seems too defeatist to embrace. A brilliant new book by my law school classmate Amy Chua, “Political Tribes,” documents the recent rise of tribalism in our politics and makes plain how hard it will be to make cross-tribal appeals, even with political platforms that are in the economic interest of many whom Chua calls white “ethnonationalists lite.” Tribal loyalties are hard to overcome.

Still, Chua concludes, there is a path to bringing at least some of these voters together through direct outreach and a shared commitment to “the American dream.” While I am not quite as optimistic as Chua about such efforts, I do believe that for practical, policy and principled reasons, it is a mistake not to try. Democrats must work as hard to unify voters as Trump is working to divide them.