The Iowa caucuses this week were a tale of two political technologies. There was Shadow Inc’s disastrous app for tallying votes, funded by a team drawn from Obama-era politics and technology, which failed due to impossible timelines, a lack of training and testing, and a likely measure of hubris. And then there was the political technology of Bernie Sanders’ campaign, which won the popular vote in Iowa.

Each of these point to differing approaches to the interaction between politics and technology in Democrat election campaigns over the past decade or so. It is the key difference between an approach characterised by mobilising (top-down and centralised) and one characterised by organising (bottom-up and distributed).

Partly by virtue of its sheer scale, US electoral politics has always been a proving ground for new deployments of political technology. The first time digital technology was adopted with real success was Barack Obama’s first campaign in 2008, which made effective use of social media that was in its infancy, putting effort into Twitter, Facebook, YouTube and, this being the 2000s, MySpace. The campaign threw $100m into technology, but it was not without its missteps: Obama’s team also created Project Houdini, a system designed to give almost real-time updates on the get-out-the-vote drive in high-priority precincts. On the day, however, the phone lines jammed and the system was a failure.

Sanders has said that Obama’s biggest mistake was, after the election, saying: “Thank you very much for electing me, I’ll take it from here.”

By the 2012 presidential election, the situation had changed. The Obama campaign’s bespoke Narwhal software marked a step up in volunteer mobilisation and microtargeting of voters. Part of its functionality relied upon a huge data mining operation – drawing from Facebook, Twitter, Tumblr and Pinterest – to find voters, discover their interests and preferences, and monitor message effectiveness and targeting. Ironically, this was the precedent for Cambridge Analytica’s infamous work. Few at the time considered the ethical implications.

Obama’s campaigns cast a long shadow over the state of technology used in the Democratic party. Especially after the defeat of the centre-left in 2016, those associated with the party in this era looked to Silicon Valley-style innovation to generate the next technical advantage: venture capital, incubators and startups. Founded by Shomik Dutta and Betsy Hoover, who had worked on both Obama’s campaigns, Higher Ground Labs emerged as an investor and incubator in new technologies to aid the Democratic party, investing $15m and funding dozens of political technology startups. And Acronym, the tech consultancy that launched Shadow Inc, was founded by Tara McGowan, a digital producer on Obama’s 2012 campaign.

Innovation in campaigning techniques is important. But that’s not always the kind of innovation that Silicon Valley recognises. In 2016, it came from Sanders’ campaign. This reflected his democratic socialist politics: it was willing to trust regular people, while employing some of the oldest campaigning tricks in the book.

Using a strategy named “distributed organising”, a small team of full-time staff was supplemented by thousands of technical volunteers, contributing to open source code repositories and creating tools that tied together commercial technologies such as Google Sheets with specialist political software. Downstream, many many more volunteers worked on the ground. The Sanders campaign did not junk data entirely, but supplemented it with face-to-face interaction. The “big data’’ of the Obama era had given way to big organising. Niche targeting of specific demographics gave way to a social democratic, universalist message regarding issues such as healthcare.

The techniques that evolved out of these campaigns have increasingly emphasised “relational organising”: placing relations, conversations and existing human networks at the centre of efforts, rather than data-based targeting. In 2020, the Sanders campaign’s Bern app is encouraging people to “have open, honest, and thorough conversations with our friends, family, and neighbours” and record their information, persuading them over the course of the campaign. This simple technique is a hallmark of traditional campaigning, but the communication power of digital technology helps it take place on a massive scale.

The key distinction between the Obama campaigns and the Sanders campaigns is the distinction between mobilising and organising. Obama’s campaign didn’t lack organising chops – Obama himself was a community organiser. But its tech functioned like a brand: it tried to mobilise people to do something. Sanders’ campaign, by contrast, is seeking to organise people, like a social movement, to do it themselves, and the tech follows this. The campaign relies heavily on supporters but, in distinction to the Obama era, makes them the centre of the campaign – they aren’t treated as volunteers who are less important than staffers, but as full participants and even experts, running whole chunks of the campaign.

The lesson is that organising tactics work best when they are enabled and supplemented, rather than replaced, by digital technology. The focus for any progressive campaign should be on building relationships, trust and power and using these to deliver political change. Yet there is something about the timescale of elections that makes this difficult.

Electoral campaigns create innovation in political technology, but they are finite and separate from most day-to-day political work. When they come to an end, the technology that enabled the campaign is quickly dropped, making it hard to develop it further, put it to other uses or build upon it.

Sanders has said that Obama’s “biggest mistake” was, after the election, saying: “Thank you very much for electing me, I’ll take it from here.” If Sanders succeeds in becoming president, the challenge for his campaign is to ensure that the movement he is attempting to build continues to have power. Seeing elections as just a tactic in a wider strategy of building power in workplaces and communities is part of the answer. If Sanders’ campaign slogan “Not me, us” is to become a reality, new and different political technologies will need to emerge, not tied to electoral cycles.

• Common Knowledge is a workers cooperative based in London. It works directly with grassroots activists to build digital technology