For all the chatter about who will get ahold of Bernie Sanders’ powerful email list of donors, one group already has it — along with the names, credit card numbers and addresses of the vast majority of his nearly 2.5 million donors.

It’s called ActBlue, a nonprofit little known outside the cloistered world of digital political circles that serves as the unsung central hub of donating via the Web for Democrats everywhere.

And the fact that Sanders used the platform — and that ActBlue gets to keep a database of Sanders supporters who collectively pumped more than $200 million into his campaign — is expected to redound to the benefit of down-ballot Democrats, from small-town council candidates to incumbent U.S. senators, all across the country.

Now, when any of those Democratic candidates sends an email to anyone saved in ActBlue’s vast catalogue of credit card accounts — which has grown exponentially thanks to Sanders — they can process donations with as little as a single click.

The ease and simplicity of the centralized system is the envy of digitally minded Republicans, who for years have failed to consolidate around a single platform, and who worry that the chasm between the GOP and the Democrats is growing only wider.

“What he’s done for the party and for ActBlue is something that every Republican would salivate over,” Vincent Harris, who served as the top digital strategist on Rand Paul’s presidential campaign, said of Sanders. “Republicans still are fragmented, siloed and left by the wayside.”

ActBlue has been around for more than a decade, but it has never before served as the primary donation tool for a major presidential campaign, let alone one powered by small donors as Sanders’ has been. In the past 13 months, Sanders helped the firm shatter nearly every internal record — for donors, contributions, stored credit cards.

In the first quarter of 2016, ActBlue raised $165 million; it had taken the company more than four years to raise that much the first time. And 5.5 million contributions were processed in the quarter — something that first took nine years to hit that mark. All those contributors, many of them Sanders supporters, are now in their database.

“Campaigns can be ephemeral. They exist. They are very important — the most important thing. And then, win or lose, they go away,” said Erin Hill, ActBlue’s longtime executive director. But the idea of ActBlue is that it lives on, she said, allowing each successive campaign to reap the benefits of the previous cycle.

The Sanders camp knows that, long after the Democratic primary is over, this is the key part of the digital inheritance it is leaving for the political left.

“Sen. Sanders’ participation in building up the Democratic fundraising ecosystem will pay dividends for progressive candidates up and down the ballot for years to come,” predicted Kenneth Pennington, digital director for the Sanders campaign.

Stored credit card information isn’t the sexiest aspect of digital politics. But it is crucial. Republicans and Democrats alike say that every streamlined step amounts to more money given.

“It’s a fact that you’re more likely to give if you have to fill out less forms,” Harris said.

Just last week, ActBlue topped 3 million people who have saved their credit card information with them. That is more than double the 1.3 million who had saved such information before the Sanders campaign began.

For a sense of scale, then-Sen. Barack Obama’s 2008 campaign, which was touted at the time as revolutionizing online fundraising, had a total of about 3 million donors.

“It will be one of the biggest legacies of the Sanders campaign,” predicted Michael Duncan, a Republican digital strategist who worked on Mitch McConnell’s 2014 reelection campaign. “The saved credit card information, the data is such an important component of what we do in digital today.”

It’s particularly important as the trend toward people contributing via mobile devices has accelerated. Single click donating is key on, say, an iPhone. “There’s nothing more painful than typing in 16 digits of your credit card number on your phone,” Hill said.

Hill said roughly 40 percent of ActBlue’s donations are now coming via mobile — double that of recent cycles.

ActBlue’s power comes from the fact that so many candidates use it, each adding new names to its database. The Democratic Congressional Campaign Committee uses ActBlue, and it recommends that House incumbents and challengers alike use the platform. So does the Democratic Legislative Campaign Committee, which helps statehouse candidates across the nation. Almost every Senate Democrat and Democratic candidate in the country uses ActBlue, too. (Hillary Clinton’s campaign has built its own donation platform, just as Obama’s campaigns did.)

ActBlue lets Democratic candidates use ActBlue for free; it charges a flat 3.95 percent processing fee on every donation. As a nonprofit, it pours proceeds beyond the fees it pays to Visa and MasterCard back into improving the site, its analytics and processing power. It churned through its billionth dollar donated earlier this year.

Zac Moffatt, who served as Mitt Romney’s digital director, said ActBlue is just like Facebook and Twitter — social networks that derive their strength in part through their size and reach. “When the number gets bigger — a 5 percent increase on a big number is a big number,” Moffatt said. “That’s what you saw with ActBlue this cycle. It took 10 years to get to one point and in a year it’s kind of doubled again, which shows you what it can do.”

“The value comes from everyone being on a shared platform. That’s where the competitive advantage comes from. The Democrats now have a competitive advantage in that regard,” he added.

Moffatt, through his firm Targeted Victory, has tried to create a for-profit GOP counterpart to ActBlue. During the primaries, his firm processed online donations for Ted Cruz’s campaign, for instance, as well as for people donating to or buying merchandise from Donald Trump. The National Republican Senatorial Committee uses the Moffatt’s platform, too.

But in a sign of how fragmented the GOP space is, the Republican National Committee uses a different donation-processing calling, called Revv, which Marco Rubio and Jeb Bush also used during the primaries. (A third company, CMDI, was used by still other candidates.)

As for Sanders, as the primary campaign wound down, he began flexing his newfound digital political muscles to reshape the Democratic Party in his own image. He recently endorsed more than a half-dozen state legislative candidates, from California to Vermont, and sent an email linking to all their individual ActBlue accounts.

His supporters began donating to them seamlessly. And in droves.

One of the lucky Sanders endorsees, Chris Pearson, who is running for the Vermont state Senate, said the single Sanders email netted him about $63,000. It was about as much as he had brought in for five past races for the state House — combined. And it all came through ActBlue.

“I feel,” Pearson said, “like I won the political lottery.”