Digital media are by their nature disruptive, and their transformational powers have left carnage across the music, book and newspaper landscape. But they also harbour the potential to remake politics. The Web and social media networks have already altered the way politics is executed, from fundraising to the data-driven micro-targeting of voters. The question is, can social media networks also change the very nature of political engagement? And, if so, will they improve democracy?

A little over a decade ago, Harvard political scientist Robert Putnam argued that the social glue that knitted Americans together and provided the backbone of civil society was coming undone. But Putnam’s lament for the declining social capital that fuelled democracy came just as the Internet was opening the throttle on social media. Now the question is not whether we are bowling alone, as Putnam’s metaphor put it, but whether those hundreds of ”œfriends” we metaphorically bowl with " texting and sharing and re-tweeting parody videos every day " form social connections that can breathe life into creaky democracies.

Empirical evidence on the political impact of social media, though growing, remains sketchy. Even so, the question is provoking increasing debate, as the writers in this issue show. The evangelists for social media contend that online networks offer new hope for greater political participation. In this view, the social media model replaces discredited political parties and foundering institutions with a new form of politics in which online activists, choosing from a buffet of social causes, can drive an agenda of change.

Not so, say skeptics, who see social media engagement as miles wide but terribly thin, lacking the characteristics such as intimacy and endurance that they contend have brought about real social change throughout history. Some warn of a dark side to social media activism, a surrender to an algorithmic culture that reinforces our biases and makes the political art of reconciling different views ever harder.

We are an impatient breed, frustrated by what we see as the failures of the politics we have, always scanning for the next big thing that might fix it. But the technology does not have to drag us along to a preordained political fate. Online activism is not inherently good or evil. We should not regard it as a new dawn or a false promise, but instead seize it as a tool, a helping hand to bridge the gap between our aspirations for the society we want to live in and the one we have.