WITH DEMOCRACY ON THE LINE YET AGAIN in November, millions of progressive voters will do what they've been conditioned to do: They'll open their digital wallets to try to save it.

A practice that initially took off among anti-Iraq War protesters in the U.S. in the early 2000s, offering smalldollar donations online has become the default mode by which Democratic-leaning voters engage with causes and candidates up and down the ballot. During the 2020 election, small donors contributed $400 million to President Biden's campaign, representing 38% of his haul.

(Though Trump's grassroots take has historically been greater than Biden's, other Republican politicians don't see as much in small donations.) The vast majority of those grassroots dollars flow through ActBlue, a Somerville, Massachusetts-based nonprofit that's become essential technology for anyone interested in supporting Democrats. Since its founding in 2004, ActBlue has processed more than $13 billion in donations.

In the wake of major events, like the Supreme Court's overturning of Roe v. Wade in 2022, links to ActBlue's battle-tested donation pages proliferate in emails, text messages, and social media posts, sending millions of dollars to Democratic coffers. ActBlue processed $90 million in the week after the Supreme Court decision alone. A slate of Democrats running on an abortion-rights platform in Virginia attracted nearly 25,000 first-time ActBlue donors last year, helping the party win back control of the state's general assembly.

ActBlue's success was far from assured during the nonprofit's early days. Its online contribution form, a stand-in for paper checks, was so revolutionary that candidates initially didn't know whether money raised through ActBlue would qualify for federal matching.