Groups gather for the Women's March on Washington on Jan. 21. Democratic officials are seeking to harness the grass-roots activism behind recent protest movements to elect their party’s candidates in 2018. (Amanda Voisard for The Washington Post)

Reid McCollum, a 34-year-old father of two from Hinsdale, Ill., was barely a month into his first foray into political activism when, on a whim in early March, he attended a protest outside the office of Rep. Peter J. Roskam (R-Ill.).

“I brought a megaphone, and there was another guy with a megaphone, and his was dying,” McCollum recalled.

That guy, it turned out, was a professional field operative with the Democratic Congressional Campaign Committee, the main national organization for electing Democrats to Congress. He invited McCollum to a small meeting the following week of fellow grass-roots activists — people who, since President Trump’s election, have organized through Facebook and Twitter and emerging progressive groups such as Indivisible and Swing Left.

From that meeting emerged the “Coalition for a Better Illinois 6th,” a group that has knocked on 8,000 doors and is intent on persuading voters in a district that favored Hillary Clinton by seven points last year to oust Roskam as he seeks a sixth term next year — and, they hope, return the House to Democratic control.

Amid ongoing tension between liberal activists and Democratic leaders, that early organizing success in suburban Chicago reflects a careful effort by party officials to harness the post-Trump surge in activists interested in electing Democrats to Congress. The officials have worked to connect them with the data and expertise the DCCC has at its fingertips but, wary of a backlash, have largely allowed them to plan and direct their own efforts without interference from Washington.

Since February, the DCCC has hired full-time paid organizers in 38 districts focused on building relationships with the grass roots. And on Tuesday, the organization is rolling out its latest effort to connect motivated activists with the national party’s resources, takeitback.com , an online “toolbox” that aims to put potential activists in direct touch with the party operatives on the ground in battlefield districts.

Democrats need a net gain of 24 seats to win the House majority, and DCCC Executive Director Dan Sena said his group’s aim is to “arm the rebels” — a conscious nod to conflicts abroad where, rather than fight every battle itself, the U.S. military has instead advised and supplied native forces most invested in winning.

[Think things will be rosy for Democrats in 2018? Not so fast.]

“We understand what is happening on the grass roots,” Sena said in an interview. “If our allies are successful at doing this, if they’re engaging people and getting them involved, we want them to be part of this. We want them to connect. We care about holding Republicans accountable. . . . How that happens, there’s no reason to fight over that. This is about putting technology behind it and people behind it, too.”

Dating back to well before last year’s election, Democratic Party leaders have been eyed with suspicion by progressives. Plenty of activists remain aggrieved over the Democratic National Committee’s apparent effort to favor Clinton over fellow presidential candidate Bernie Sanders, and the DCCC has been the subject of rampant second-guessing after gaining only a handful of seats in 2016.

One week after cancer patient, Rosa Segal, finished her final round of chemotherapy, she traveled five hours by bus to join the Women's March in D.C. Segal protested with her daughter, Eddy, against the repeal of Obamacare and the preexisting condition provision. (Zoeann Murphy,McKenna Ewen,Rhonda Colvin/The Washington Post)

That has been compounded by Democrats’ expensive loss in a June special election in Georgia, and the party’s hesi­ta­tion to invest heavily in Democrats running in other recent special elections. But so far, grass-roots organizers are giving positive early reviews of the DCCC’s effort to encourage and coordinate with the liberal activists flocking toward the midterms through new online channels.

“I’ve been organizing for 20 years, and I’ve never seen this much grass-roots energy,” said Matt Ewing, chief community officer for Swing Left, which has attracted more than 300,000 volunteers. “And I think it’s very smart of the Democratic Party to recognize that the best way to leverage that energy is to support it versus trying to narrowly funnel it. That, to me, is great news.”

Ewing said that the impact of the party operatives has been evident in his conversations with activists in various battleground districts across the country.

“They tell me about all the great Indivisible groups they are working with, the Sister March huddles, the local Democratic county clubs, and then they tell me about this great organizer that’s been placed there by the DCCC who’s helping them with their training and infrastructure,” he said. “They’re not coming in hard-charging, but our experience is they are setting up trainings, they’re building relationships, they’re supporting our volunteers on the ground. And that’s the type of posture that we need the Democrats to be doing more of.”

The involvement of the party organizers varies from district to district. In Illinois, for instance, the grass-roots group McCollum helps run keeps its distance from party organizations for legal reasons. But the DCCC organizer sends potential volunteers toward the grass-roots coalition rather than try to duplicate its canvassing efforts under the national party’s aegis.

In California’s 39th Congressional District, when Democrats are seeking to oust 13-term GOP incumbent Edward R. Royce, the party operative there is working directly with volunteers — many of them who connected through Swing Left and Indivisible and other activist groups.

“When I wanted to do something, I did not go to the Democratic Party; I went to Swing Left,” said Bonner Meudell, a retiree from Sierra Madre, Calif., volunteering to help unseat Royce. “I don’t even know why, but it just never entered my mind to go to the Democratic Party. That didn’t seem as alive.”

But the training, tools and data provided by the DCCC organizer, Meudell said, have become an integral part of her efforts. “I had never set foot canvassing or doing voter registration before April of this year, and now I’m training and leading,” she said. “And I doubt that we would have made this progress without him very gently guiding and leading us.”

The Democrats’ efforts are unusual in coming well before the electoral landscape in many of these battleground districts is close to settled. Numerous Democratic candidates have stepped forward to run for many of those seats, and progressives have frequently been frustrated in the past by party officials in Washington favoring certain candidates — often the more moderate candidates — over others.

Those tensions may reemerge as the midterms approach, some of the activists predict, but the early collaboration is paying dividends. Besides the relationships that have been built and the infrastructure that has been established, voter data gathered by grass-roots activists is being funneled back into party databases, ready for the eventual Democratic nominees to take advantage.

Sena said the DCCC’s new website will offer new tools for activists ranging from novices who simply want to know about events in their neighborhood to more experienced political hands who want to know more about social media campaigns, voter registration or get-out-the-vote drives. One function, “Claim Your Precinct,” helps users get involved at the most granular level of politics — inviting them to become a “captain” of a voting precinct and connecting them with a Democratic field organizer to guide their efforts.

Those efforts will be coordinated by the party’s growing staff of field operatives, but much of the district-by-district specifics in the online toolbox — ranging from meetup listings to social-media content — will be generated by volunteers without any affiliation with the party.

“I think the fact that the party committee’s willing to not make this look, feel, and sound like it’s the party committee doing it and just allowing the grass roots to build this, I think is incredibly novel,” Sena said. “I think it is smart to give local people the tools to do it themselves.”