DONALD TRUMP, THE Republican front-runner for the American presidency, is clearly riding a wave of anger—but he is also wielding a huge virtual megaphone to spread his populist messages. “@realDonaldTrump”, the Twitter account of the property magnate turned politician, has more than 7m followers and the number is rising by about 50,000 every day. Moreover, since each of his tweets is re-tweeted thousands of times and often quoted in mainstream media, his real audience is much bigger. And if he does win the Republican nomination, it will be hard to tune him out. “How do you fight millions of dollars of fraudulent commercials pushing for crooked politicians?” he tweeted in early March. “I will be using Facebook & Twitter. Watch!”

If Ted Cruz, his fellow Republican, were to clinch the nomination, the campaign for America’s presidency would be quieter—but no less digital. Mr Cruz’s victory in the Iowa primaries was based on effective number-crunching. He bombarded potential supporters with highly targeted ads on Facebook, and used algorithms to label voters as “stoic traditionalists”, “temperamental conservatives” or “true believers” to give campaign volunteers something to go on. He also sent official-looking “shaming” letters to potential supporters who had previously abstained from voting. Under the headline “Voting Violation”, the letters reminded recipients of their failure to do their civic duty at the polls and compared their voting records with those of their neighbours.

The way these candidates are fighting their campaigns, each in his own way, is proof that politics as usual is no longer an option. The internet and the availability of huge piles of data on everyone and everything are transforming the democratic process, just as they are upending many industries. They are becoming a force in all kinds of things, from running election campaigns and organising protest movements to improving public policy and the delivery of services. This special report will argue that, as a result, the relationship between citizens and those who govern them is changing fundamentally.

Incongruous though it may seem, the forces that are now powering the campaign of Mr Trump—as well as that of Bernie Sanders, the surprise candidate on the Democratic side (Hillary Clinton is less of a success online)—were first seen in full cry during the Arab spring in 2011. The revolution in Egypt and other Arab countries was not instigated by Twitter, Facebook and other social-media services, but they certainly helped it gain momentum. “The internet is an intensifier,” says Marc Lynch of George Washington University, a noted scholar of the protest movements in the region.

In the course of just a few years digital technology has become an essential ingredient in any protest movement. The Arab spring is just one example of how the internet has facilitated political mobilisation. Others include the civil unrest in Istanbul’s Taksim Gezi Park, the Maidan protests in Ukraine and the Umbrella Movement in Hong Kong, all in 2013 or 2014. In America the main instances have been Occupy Wall Street in 2011 and more recently Black Lives Matter, a campaign drawing attention to violence against African-Americans. In Europe, Spain’s Indignados, an anti-austerity coalition, in 2011 became the first big protest movement to make extensive use of social media. Even Islamic State relies on its online propaganda and messaging apps, which allow the self-styled caliphate to recruit new fighters and keep in touch with those on the ground.

However, this special report will argue that, in the longer term, online crusading and organising will turn out to matter less to politics in the digital age than harnessing those ever-growing piles of data. The internet and related technologies, such as smartphones and cloud computing, make it cheap and easy not only to communicate but also to collect, store and analyse immense quantities of information. This is becoming ever more important in influencing political outcomes.

America’s elections are a case in point. Mr Cruz with his data savvy is merely following in the footsteps of Barack Obama, who won his first presidential term with the clever application of digital know-how. Campaigners are hoovering up more and more digital information about every voting-age citizen and stashing it away in enormous databases. With the aid of complex algorithms, these data allow campaigners to decide, say, who needs to be reminded to make the trip to the polling station and who may be persuaded to vote for a particular candidate.

No hiding place

In the case of protest movements, the waves of collective action leave a big digital footprint. Using ever more sophisticated algorithms, governments can mine these data. That is changing the balance of power. In the event of another Arab spring, autocrats would not be caught off guard again because they are now able to monitor protests and intervene when they consider it necessary. They can also identify and neutralise the most influential activists. Governments that were digitally blind when the internet first took off in the mid-1990s now have both a telescope and a microscope.

But data are not just changing campaigns and political movements; they affect how policy is made and public services are offered. This is most visible at local-government level. Cities have begun to use them for everything from smoothing traffic flows to identifying fire hazards. Having all this information at their fingertips is bound to change the way these bureaucracies work, and how they interact with citizens. This will not only make cities more efficient, but provide them with data and tools that could help them involve their citizens more.

This report will look at electoral campaigns, protest movements and local government in turn. Readers will note that most of the examples quoted are American and that most of the people quoted are academics. That is because the study of the interrelationship between data and politics is relatively new and most developed in America. But it is beginning to spill out from the ivory towers, and is gradually spreading to other countries.

The growing role of technology in politics raises many questions. How much of a difference, for instance, do digitally enabled protest surges really make? Many seem to emerge from nowhere, then crash almost as suddenly, defeated by hard political realities and entrenched institutions. The Arab spring uprising in Egypt is one example. Once the incumbent president, Hosni Mubarak, was toppled, the coalition that brought him down fell apart, leaving the stage to the old powers, first the Muslim Brotherhood and then the armed forces.

In party politics, some worry that the digital targeting of voters might end up reducing the democratic process to a marketing exercise. Ever more data and better algorithms, they fret, could lead politicians to ignore those unlikely to vote for them. And in cities it is not clear that more data will ensure that citizens become more engaged.

When the internet first took off, the hope was that it would make the world a more democratic place. The fear now is that the avalanche of digital information might push things the other way. Viktor Mayer-Schönberger, a data expert at the University of Oxford, sums up the problem: “Data are mainly helping those who already have information power.”