A year ago yesterday, a handbook, written by former congressional staffers and outlining a path of useful action for those disturbed by the election of Donald Trump, appeared online. It was called “Indivisible: A Practical Guide for Resisting the Trump Agenda,” and it has since helped instruct new activists seeking to elect progressives—or at least prevent the election of more conservatives—around the country. The resulting group now has six thousand chapters. Six months ago, an Atlanta Indivisible chapter got behind the insurgent campaign of Jon Ossoff, the young Democrat aiming to flip a historically Republican congressional district in the Atlanta suburbs. Ossoff lost the highly publicized race for many reasons—including his youth, his residence slightly outside the district, and, arguably, the cautiousness of his message. Democrats close to the Ossoff race might also point to the volume of Republican super-PAC attack ads that aired during the extremely expensive campaign. Another possible factor: Indivisible did not have the resources that it does now, which it just used to help elect Doug Jones in Alabama.

“The capacity we had during the Georgia Sixth race was much more limited,” María Urbina, Indivisible’s national political director, told me yesterday. “It was more like a help desk: we were trying, from afar, to help support groups when they reached out for guidance.” Now, she said, “we’re paying for an app, training volunteers on it, and paying for staff to be down there to support knocking, calling, everything. That’s a much different level of engagement and investment.” The group also has access to voter files, and all of this “allows our locals to hit the roads a lot faster.” Maybe the result in Georgia would have been different if they’d had these things at the time, Urbina suggested. “Who knows.”

A number of other progressive groups, both local and national, worked to propel Jones to his unlikely victory. Among them were Alabama’s N.A.A.C.P. chapter, which, according to the journalist Al Giordano, instructed its local branches to call every registered Alabama voter who did not vote in the 2016 Presidential election. Woke Vote, the Working Families Party, MoveOn—and, as AL.com reported, “a former sharecropper in an S.U.V.”—also helped lead to high turnout numbers among Democrats, particularly in African-American communities. African-Americans make up twenty-seven percent of Alabama’s population, and they comprised almost thirty per cent of voters in the election; ninety-six per cent of African-Americans voted for Jones. The Jones campaign itself was also effective in this effort, as I witnessed while walking around predominantly African-American neighborhoods in Montgomery, a few days before the election, with volunteers working to get out the vote and distribute yard signs.

But Indivisible’s efforts appear to have been particularly well targeted. Of the six counties that the group focussed on in Alabama, three of them—Madison, Lee, and Mobile—flipped from having a majority of their voters select Trump last November to a majority choosing Jones. In the other three counties where it knocked on doors, made calls, and sent the majority of its texts—Houston, Dale, and Henry—the G.O.P.’s winning margins shrank by more than twenty points. Steve Bannon, speaking on a Breitbart radio program after Jones defeated Roy Moore, whom Bannon repeatedly stumped for, acknowledged the effectiveness of the collective progressive ground game. Bannon told Breitbart’s editor-in-chief, Alex Marlow, “You’ve gotta give the devil its due.”

Though its resources have grown dramatically in the past year, Indivisible’s footprint in Alabama, like that of the Democratic Party, was relatively small prior to the race between Jones and Moore, the Trump-backed Republican. “There’s really great local organizations, especially in Alabama’s African-American community,” Urbina told me. “But, in terms of infrastructure and party apparatus, it’s quite lacking there.” In September, there were five Indivisible chapters in the state, the biggest of which was in Huntsville, a bluish city in the north, which regularly draws a hundred members to its protests and meetups. During the Jones campaign, Indivisible’s five local chapters knocked on fifty-five hundred doors to get out the vote. “We had a lot of Alabamians talking to Alabamians,” Slate Goodwin, a twenty-seven-year-old member of the Huntsville chapter, told me yesterday. “Not a whole lot of out-of-staters knocking or calling. It was mostly here in the community, and I think that really played a huge role.”

Still, Indivisible exerted an out-of-state influence, too. “We did help supplement the local chapters with text messages from our entire network coming into Alabama,” Urbina told me. According to the group, fifteen hundred national Indivisible volunteers sent two hundred forty-two thousand and four hundred texts to likely Democrat voters, reminding them to vote and to make a plan to do so. Indivisible had three staff members on the ground for the entire final week of the campaign, helping locals canvass in what a number of Alabamians described to me as the biggest get-out-the-vote campaign for a Democrat since Barack Obama’s efforts in the state back in 2008.

Urbina is, of course, pleased with Jones’s victory. But she and others at Indivisible are just as proud of another outcome: a new Alabama chapter of the group, located in Dothan, was launched during the campaign. “That probably doesn’t seem huge,” she told me, “but in Alabama, where capacity has lacked over the years, we’re thrilled.” She went on, “Our view is that these groups will take the skill sets learned in building their own mini-campaigns, and they’ll use them to further grow and show their communities that they’re serious about building infrastructure there. That’s how this movement will be sustained.”