Democrats lost the Rust Belt in November in part because they lost the white, working-class, as my colleague Ron Brownstein has written. They failed to offer a more compelling message than Donald Trump’s pledge to stomp out trade deals and bring manufacturing jobs back from overseas.

The presidential election wasn’t the only race in which Democrats lost white, working-class voters who had traditionally gone blue. They lost the seats they had targeted in Ohio, Wisconsin, and Michigan. They did poorly in majority white states such as Minnesota and Iowa, where the state Senate switched from Democrat to Republican.They lost the governorship of Indiana, which polls had predicted would go to the Democrat, and the governorship of Missouri, the western-most Rust Belt state, which had been occupied by a Democrat, Jay Nixon.

If they want to win future elections, Democrats are going to have to find something better to say in the Rust Belt. Their current message is not resonating with residents who have seen manufacturing jobs disappear and who want to return their towns and states to how things used to be. Democrats “remain obsessed with cultural issues,” University of California-Hastings professor Joan C. Williams wrote, in a Harvard Business Review essay shortly after the election. “I fully understand why transgender bathrooms are important, but I also understand why progressives’ obsession with prioritizing cultural issues infuriates many Americans whose chief concerns are economic.”

But the question is what Democrats should say. The biggest problem Democrats face now, and will face in the future, is that there are no simple solutions to the economic crisis in the Rust Belt. Democrats have tried, with proposals like infrastructure projects, science and technology education, and tax credits for companies that offer apprenticeships, but few of the policy prescriptions that could begin the process of getting millions of white, working-class men back to work are very sexy. “There’s no silver bullet,” Ned Hill, a professor at Ohio State University and the faculty affiliate for the Ohio Manufacturing Institute, told me. “This is an adult conversation so easy answers aren’t there.”

Hill says that one way to create jobs in the Rust Belt is to bolster apprenticeship programs so that unskilled workers can get trained in some of the hundreds of thousands of jobs now going unfilled. Another is to model the manufacturing system on the one in Germany, where public-private institutes translate research into potential commercial products, and detailed educational pathways help train students for jobs that will be in demand. “We’ve lost the ability to train a sophisticated manufacturing workforce,” he said. One-fifth of the German workforce is employed in manufacturing—double the U.S.’s share.

Indeed, many of the economists I talked to when looking for answers for the Rust Belt mentioned retraining. After all, the Rust Belt lost manufacturing jobs, but it enjoyed growth in other industries. While the states of Illinois, Indiana, Michigan, Ohio, Pennsylvania, and Wisconsin, saw manufacturing employment fall 30 percent—losing 1.4 million manufacturing jobs between 1996 and 2016—employment in health and educational services grew 43 percent in those states over the same time period, according to data from the Bureau of Labor Statistics.

What’s more, the U.S. is about to go through a boom period as technologies such as robotics, self-driving cars, and genomics mature, says Bruce Katz of the Brookings Institution. Cities such as Pittsburgh, a robotics center, and Milwaukee, which has become a pioneer in water technology, will add jobs related to these technologies and the industries that help support them.

“It takes a bit more sophistication to be thinking through this stuff than, ‘All trade deals are bad,’ he told me. “We’re talking about the interplay of R&D, entrepreneurial growth, trade, and infrastructure, and there are a lot of different pieces to it.”

Still, terms like public-private partnerships, infrastructure investment, and workforce development don’t exactly excite people. And the idea of retraining men who had worked in manufacturing for jobs in healthcare or education often isn’t an appealing prospect. Many workers don’t show up for free retraining courses, as I’ve written about before, sometimes because the prospect of going back to school is intimidating, other times because they fear there won’t be jobs once their retraining is over. “The idea of ‘training people’ is a wimpish answer—there are only so many people who can do air conditioning repair,” Dave Robertson, a political science professor at the University of Missouri–St. Louis, told me. “The question is, how are we going to get jobs that make people feel proud again.”

Another strategy might be to double down on the importance of unions and other structures that will help workers earn more. That includes advocating for higher wages, better legal protections for part-time workers, and more robust retirement and health benefits. It could also mean talking more about anti-trust policies that could address some of the growing monopolies that have led to industry consolidation and job loss across the United States. “I think the goal is what Bill Clinton announced, which is good jobs at a good wages, and, I should say, good incomes, for hard-working people,” Robertson, at the University of Missouri, told me. “That’s what Democrats were really remiss at talking about in this election.”

Indeed, many of the voters who switched from blue to red in this election were one-time union members. And Republicans would be hard-pressed to say that the GOP is the party of unions, or worker benefits. Trump advisors have said he is seeking advice from Wisconsin Governor Scott Walker, who systematically disassembled public-sector unions in his state; Vice-President-elect Mike Pence made Indiana a right-to-work state, making it harder for unions to recruit and keep members, during his tenure.

Yet talking about better jobs for better wages is tough because Democrats have been in charge for eight years nationally, and during that time, they haven’t been able to affect much change in wages. Full time wage and salary workers have seen their earnings grow just half a percentage point when adjusted for inflation, since Obama took office, according to data from the Bureau of Labor Statistics. There are still 5.9 million people working part-time for economic reasons, which is fewer than a few years ago, but higher than the years before the recession; a decade ago, only around 4 million people were part-time for economic reasons. Many of these workers live in Rust Belt states that were once home to good manufacturing jobs.

This underscores the grim reality that both parties have to face. There’s a very real possibility that no amount of investment or retraining can replace the manufacturing jobs that have been lost. It’s been decades, after all, since the North American Free Trade Agreement, and nearly as long since China entered the World Trade Organization in 2001. Despite both Democratic and Republican administrations since then, there has been no reversal of fortunes for the Rust Belt.

This is not the uplifting message that either party will want to embrace on the campaign trail. The most effective solutions to it aren’t going to be popular: They include helping people move to areas where there are jobs, and providing wage subsidies for those who can’t. And that may mean that they never come to pass.