Longtime labor advocate Kamala Harris and longtime National Education Association member Tim Walz accepted their nominations last week at the most pro-union Democratic National Convention in the party’s history. The challenge now is to translate the energy of the convention into a campaign that boosts turnout among the multiracial, multiethnic mass of working-class Americans—especially young people—who will decide whether the party’s ticket wins, and perhaps wins big, in November. To do this, Harris and Walz must take a lesson from what worked at the convention in Chicago and make a discussion of unions central to their fall campaigning.

Every speech that Harris and Walz deliver this fall should include a section that explains what the election of a Democratic president and a Congress with solid Democratic majorities would do to strengthen unions. That’s practical politics in an era where Americans are showing unprecedented levels of enthusiasm for organized labor.

Seventy percent of Americans approve of unions, according to Gallup polling released in anticipation of Labor Day. That’s up from 67 percent last year, when Gallup found that 88 percent of likely Democratic voters have a favorable view of unions, while a striking 61 percent of them want unions to have more influence on the economy and society. That same Gallup Poll found that 47 percent of Republicans approve of unions, while 21 percent want them to have more influence.

Even more notable than the partisan numbers are the astronomical levels of support for unions among young people, who can give Democrats winning margins in presidential battleground states and congressional contests if they turn out at high rates. Polling last year by the AFL-CIO found that 90 percent of Americans under the age of 30—no matter their party affiliation—support strikes by union members, while roughly the same percentage approve of unions.

If the Democratic Party unequivocally brands itself as the party of organized labor in this campaign, it will benefit the party on Election Day. This isn’t just a matter of reaching out to existing union members. It’s a matter of speaking to the many millions of Americans who want to join unions but who have been blocked from doing so by the barriers that Republicans have erected to organizing and collective bargaining. In Republican-controlled states, those barriers include anti-labor “right-to-work” laws, which make it dramatically harder to organize and maintain union locals; and at the national level, GOP senators have opposed labor law reforms such as the Protecting the Right to Organize (PRO) Act, which would open up new avenues for organizing and protect workers who want to unionize from being intimidated by corporations.

In a race against alleged billionaire Donald Trump, who as president packed the National Labor Relations Board with anti-union members, and against the Republican members of Congress whose lockstep opposition prevented President Biden and Senate Democrats from enacting the union-backed PRO Act, there’s a clear distinction between the two major parties. Democrats should seize on every opportunity to highlight that distinction.

That’s what many of the savviest speakers at the Democratic National Convention did, to powerful effect. Indeed, every time that the “u” word was mentioned in Chicago, pandemonium ensued.

On the first night of the convention, when Joe Biden declared, “I’m proud to be the first president to walk a picket line,” the crowd roared its approval so loudly that even Biden seemed a bit taken aback. But the president wasn’t stopping there. “I’ve been labeled the most pro-union president in history,” he noted, as the applause built to a crescendo. Then, to no one’s surprise but to everyone’s delight, he embraced the label, announcing, “I accept it; it’s a fact. When unions do well, we all do well.” The 20,000 delegates alternates and party partisans who had packed the United Center, in the great working-class town of Chicago, answered their president with a thunderous round of applause.

It wasn’t just an applause line for Biden, whose valedictory address after turning the party’s nomination over to Harris was always going to be an emotional highpoint of the convention.

Every speaker who mentioned organized labor was greeted with sustained, often overwhelming, enthusiasm. It happened when United Auto Workers Union president Shawn Fain preached the union gospel and then, with a nod to a 2002 rap hit, pulled off his jacket. “In the words of the great American poet Nelly, ‘It’s getting hot in here,’” Fain observed, to the crowd’s applause, as he revealed that he was wearing a “Trump is a scab” T-shirt. It happened when American Federation of State, County and Municipal Employees Union President Lee Saunders explained that Harris was “guided by a basic principle: more freedom for working people, including then freedom to join a union.” And when Saunders gave voice to organized labor’s “Union Yes!” battle cry, the entire hall echoed his message.