Voters fill out primary ballots at a Des Moines polling place last year. (Scott Stewart/AP)

Most candidates agree that “grass-roots engagement” and a good ground campaign matter, but too often candidates misunderstand what actually makes them work.

People power is not a spigot that can be turned on and off with fancy technology. Instead, it depends on interwoven human networks through which people learn to work together on things they care about, even when the electoral spotlight is not on. Campaigns, and political parties, can help build these networks — or make them wither away. In 2009, national Democrats opted to let them wither. They’re back at that crossroads today.

2018 was a standout year for voter engagement. According to data provided by NGP VAN, the voter file provider for Democratic campaigns and independent groups up and down ballot, supporters of Democratic campaigns knocked on more than 155 million doors in 2018, a 60 percent increase over the previous midterm election and a full 40 percent more than in the 2016 presidential election year.

Today, just as in 2009, the consultants and vendors who earned millions of dollars on the last election are eager to attribute victory to new technology (today it’s voter-to-voter tools like Hustle and VoteWithMe) or to “radical” campaign structures, like Beto O’Rourke’s in Texas.

Dropped from view are the millions of volunteers who worked for the “blue wave,” and, as important, the local structures that made their participation possible — and will determine what their future impact will be.

The success of Barack Obama’s 2008 and 2012 field campaigns renewed attention on the ground game after decades in which campaign managers spent more time worrying about the “air wars” of TV and radio ads. Beginning in 2007, the campaign built Obama for America into a volunteer behemoth through neighborhood-based relational organizing, in which small numbers of staff members trained volunteers to recruit and lead others. By 2012, this strategy yielded 2.2 million volunteers, organized by 10,000 unpaid neighborhood team leaders, with 30,000 additional volunteers working as core team members. This volunteer machine registered over 1.8 million voters, made more than 150 million phone calls and ran 5,177 get-out-the-vote staging locations on Election Day.

Yet after the groundswell that carried Obama to office in 2008, Democratic leaders dithered about who should “own” Obama for America, eventually deciding to turn it over to the Democratic Party. Once it became a party-run organization, party leaders sought to quash dissent, discouraging volunteer leaders from opposing the Obama administration and treating Obama for America more like a publicity list than a human ecosystem. The relationships, spaces of self-governance and concrete community-based goals that gave the 2008 campaign its energy dissipated.

By turning Obama for America into a commodity, the party stripped it of value.

In contrast, tea party anger on the right translated into high-impact organizing, as new local groups supported and held accountable Republican candidates for school boards and state legislatures across the country. Instead of silencing tea party dissenters, Republican leaders negotiated with them, allowing local leadership to grow. This investment laid the foundation for the GOP “shellacking” of Democrats in the 2010 midterms and the down-ballot victories Republicans racked up from 2009 to 2016 even as Obama won reelection in 2012 and Hillary Clinton won more overall votes than Donald Trump in 2016.

But the left has seen a resurgence of local organizing since 2016. After Trump’s election, new grass-roots groups came together and dived into action, mostly without guidance from the Democratic Party. In some cases, the energy flowed into long-standing community organizing networks like Faith in Action and the Center for Popular Democracy or local chapters of organizations like the ACLU. New networks also offered inspiration and tools for group-formation, including Indivisible, Swing Left, Sister District, the Women’s March and March On. At the same time, emerging local groups developed unique regional priorities, embracing campaigns from Medicaid expansion in Idaho to ranked-choice voting in Fargo, N.D., to public campaign financing in New York, to school board elections all across America’s once-red suburbs.

This year-round work formed the springboard to the blue wave and massive participation of 2018. You don’t get 155 million door knocks from early adopters alone. You get them from active local networks building outward.

Unlike previous volunteer surges on the left, including the Obama ’08 campaign, these new activists sought to join local Democratic Party organizations as well. By now, two years into the process, most grass-roots groups we know have multiple leaders who are also elected members of their local or county Democratic committee. These volunteers have learned a fundamental rule the national campaigns continue to ignore: Local structures matter.

Democratic Party leadership gives rhetorical attention to the grass roots. But instead of investing in local party offices and recruiting, training and listening to local leaders who can nurse year-round relationships, the party puts more resources into tools and national communications. With that approach, come election time, voters are merely data points instead of humans enmeshed in a latticework of local relationships.

Yet from blue metropolitan areas to conservative rural counties, grass-roots activists are pushing from within for a different approach, running slates of officers who have hands-on experience as campaign “super volunteers” and believe passionately in precinct-level relationship-building. Some longtime local Democratic leaders, however, seem more interested in maintaining control of endorsements and alliances than having local parties fulfill their nominal mission of outreach and engagement.

When commentators hype minuscule ideological differences among 2020 Democratic hopefuls as “a struggle for the soul of the party,” they are missing the real fight. Voices from within are demanding transparency and action from their local Democratic parties. It’s not a struggle over policy direction, but instead a struggle to turn local parties into real spaces of democratic access and make themselves heard within a national party structure that largely ignores local leaders.

Pundits on the left have gone from chiding that protests don’t change politics to lamenting that people aren’t protesting enough — without stopping to notice the crucial base-building work, far beyond protests, that has been underway all along. Grass-roots stalwarts know that obsessing over 2020 polls will not keep democracy afloat. Instead, they have embraced the grinding, glamour-free work of building change: rewriting bylaws, recruiting for municipal office, pushing referendums that ensure every vote counts.

National Democratic leaders and funders can support those efforts now and reap the benefit in engaged volunteers and voters when 2020 arrives. Or they can repeat the mistakes of 2009 all over again.