Could the internet be bad for democracy? Surely not. Electronic democracy, or e-democracy for short, is an idea whose time is approaching. The government is about to launch an e-democracy white paper, and a cabinet committee on the issue is up and running. The e-minister, Douglas Alexander, is not alone when he suggests that "new technology will help to empower people, encouraging them into and strengthening the democratic process".

Falling turnout, declining levels of civic engagement and widespread political disaffection among young people make the internet a tempting path towards democratic redemption. Whether Labour’s plan for e-voting and online consultations will work is not at all certain, but it is worth a shot. Yet there is growing concern that the internet may be a “disruptive technology” for democracy. This concept remains one of the handiest ways of explaining the internet boom. Clayton Christensen, the Harvard academic who coined the term, suggests that new technologies tend to undermine the success of existing businesses, generally without anyone noticing until it’s too late.

In The Innovators’ Dilemma, Christensen suggests that there are two broad types of technologies; those that sustain, and those that disrupt. Put simply, sustaining technologies improve existing systems and companies; those that disrupt undermine them until they collapse. The two types are notoriously difficult to tell apart – that is, until you go bust. They also neatly explain why clever companies, run by clever people, often trip over the trick they missed. Disruptive technology became especially popular during the "innovate or die" heyday of the dotcom economy. Self-destruction was to be applauded: not destroying your own company was for wimps. Yet the notion that technology can have a damaging effect on existing institutions remains true. Perhaps more importantly, if those institutions happen to be democratic rather than economic, the game is more dangerous. Democracies are not companies; they need careful and considered nurturing rather than the occasional shock to the system. It is not generally thought wise to laud their creative destruction.

The current consensus is that new media has a sustaining effect on democratic practice. Yet the power of the internet sits uneasily next to political institutions. A means for direct connection between individuals, it lends itself to a more direct form of democracy in which engaged citizens can demand a less interrupted relationship with political power. Networked technologies are also powerful tools for protesters, well demonstrated by the virtual world that co-ordinates the anti-globalisation movement. Combine the two, and you can imagine a world where demand for political connection increases, without any commensurate increase in the capacity of democratic institutions to cope.

This has already begun to happen in America. Congress will receive well over 100 million e-mails this year, a figure that has doubled in three years. To put it another way, an institution designed for the 18th century now receives more messages in one year than in the whole of the 19th century. It is already becoming difficult to separate bogus lobbying campaigns from genuine constituent communication, and overstretched congressional staffers struggle to respond to constituent demands. This democratic overload occurs in sudden floods, often orchestrated by campaigns manipulating public sentiment for high-profile causes. Yet precisely because new media makes access to information and direct communication easier, it simultaneously increases demands while decreasing the capacity of democratic institutions to respond effectively.

Such problems may be transitory, requiring only greater resources and expertise to help representatives cope better. But others may be less easy to fix. A greater threat comes from the way in which citizens seek and use information to think about political issues. The author Steven Clift pre-emptively protects e-democracy from unhelpful hype by arguing that "just as the television saved democracy, so will the internet". Yet herein lies the strongest potential for technology to chip away at democratic practices: by changing the way citizens think about political issues.

Last year, the respected American legal theorist Cass Sunstein suggested exactly this. His book, unwisely titled Republic.com, argues that converged media, and specifically the internet, will allow citizens to choose precisely the information they receive. In particular, it will allow them to choose what they do not receive. This is the danger of the "daily me" culture, where “the growing power of consumers to ‘filter’ what they see” will create information ghettos and isolated citizens. These enclaves will in turn undermine the idea of a public realm in which a healthy mix of facts, ideas and opinions greases the wheels of participatory democracy.

Republic.com argues that a “heterogeneous society” needs two things. First, citizens should be exposed to new ideas through “unanticipated encounters”. Second, we need a range of "common experiences" to allow a grown-up approach to social problems. These two planks prop up a “public space” in which social beings work out their differences and co-operate to mutual advantage. Without them, government will become as factional and splintered as the communities beneath it.

Two analogies, one humorous, the other serious, might help to explain. The satirical website satirewire.com ran a story some months ago with the headline "Americans annoyed by all this international crap on internet". The article, with the sub-head "web’s increasingly worldly flavour threatens Americans’ world-view", joked that it was impossible to avoid foreign news online. Sunstein disagrees. He thinks that the internet allows users to avoid completely opinions they dislike. New media allows perfect and splendid isolation.

The second analogy comes from a recent article in the Economist entitled "America’s New Utopias". Detailing the rapid rise of gated communities, even the paragon of free-market journalism seemed troubled that one in six Americans now live in exclusive, white and often guarded housing communities. For housing or community read media or content, and you have the gist of the “daily me” dilemma. In this sense, the internet in particular and new media in general could be disruptive technologies. The stable basis of participatory democracy, the need for something in common to help overcome the things on which we disagree, could be gradually eroded. Politics, the process of getting over these disagreements, could be undermined.

Will it happen? There are plenty of reasons to doubt the "death of the public realm". Filtering and choosing information is nothing new. People are already adept at changing channels, flipping pages and buying newspapers that do not test their patience with difficult foreign news. In many senses, the media has never represented a cohesive "public sphere" but a loose collection of views chosen by viewers or readers. Moreover, to suggest that old media is in some way conducive to political discussion neatly glosses over the long-running trend towards common-denominator programming. Another American theorist, Shanto Iyengar, makes this point: "Even in the more prestigious journalistic forums, news content is characteristically shallow."

However, the internet is different in one important respect. Users have to seek out information. Whereas television is generally suited for sedentary media herbivores, new media privileges information hunter-gatherers. Using the internet, and to a certain extent digital television, means searching for useful information rather than waiting for it to be placed in front of you. If people choose to look in only certain places, the chances of running across something by accident decrease. This idea – the media hunter-gatherer seeking his or her "daily me" – does suggest a rather unusual type of critical consumer, armed with extremely specific interests and the knowledge to pursue them. This may be a function of the extremist case studies employed by those who worry about internet information enclaves. Quasi-fascist groups, religious fanatics and mountain militias make for dramatic examples but are not in any way representative of the political mainstream.

Yet the risk of disruption remains. Most evidence suggests that the online majority take little advantage of what Manuel Castells called The Internet Galaxy. Instead of hunting down variety, they tend to search for deeper information on familiar topics or areas. The same is true of television, where digital users tend to watch the same type of programmes but in greater number.

In this way, new media is a force for narrowness, not diversity. It can also atomise rather than heal existing social divisions. In the longer term, it may be disruptive. The next decade will see networked technologies exerting a much more questionable impact on the plumbing of democracies, in a greater degree than the government’s current vision of electronic empowerment suggests. And here lies the irony. If the internet turns out to be a disruptive technology for democracy, the potential for disturbance is twinned with an even greater potential for reinvention. The trick will be to spot potential problems early, and work out ways to cope. So, could the internet bad for democracy? Of course it could. Guardians of democracy must think quickly to prevent a potential electronic tragedy of the commons.

James Crabtree works on the iSociety technology research project: www.indsoc.co.uk/isociety