Without online technologies, Barack Obama would never have gotten past the primaries. Had Facebook, YouTube, texting, a 13-million name email list and a website developed by Facebook co-founder Chris Hughes been absent from his campaign, he would never have raised enough money, been seen and heard by enough people, or enlisted enough volunteers. Yet progressive hopes are faltering, not only because of Obama's compromises and mistakes and Republican intransigence, but also because far too many of his supporters have come to believe they can act exclusively through these online technologies, to the exclusion of face-to-face politics.

Think about your own political participation since Obama took office, and compare it to 2008. You've probably signed online petitions, clicked to contact your representatives, maybe commented on political blogs. These are valuable activities. I do some most every day. But they aren't the same as knocking on doors, making phone calls, talking politics with people who may disagree with you, and doing all the other things that created the 2006 and 2008 Democratic victories. They also aren't the same as rallying in the streets, attending town meetings, picketing the offices of predatory corporations or destructive politicians, or working in other visible ways to shift America's political culture and pressure on our elected officials to genuinely address our urgent crises. Since November 2008 it's been the political right that's largely dominated public discussion, even though their policies have created our vast array of problems to begin with. Of course they have the advantage of a shameless echo chamber, from Andrew Breitbart to Rush Limbaugh and Fox. But the grassroots right has also been more active on the ground, while those of us who helped elect Obama have acted in mostly virtual ways, leaving us all too often invisible and unheard.

This dual aspect of online engagement isn't new. It's been building since the Internet came of age. But it's worth looking both at how technologies that we now take as for granted as the air we breathe have both empowered us politically and created new traps.

We now expect that organizations that would once have reached us through expensive mailings or time to contact us via the internet. As action alerts arrive in our inbox, we click and sign, and our Congressional representative receives the letter or petition du jour. Or a group we support sends out a video of an ad it wants to run on network television, we donate $25 (along with 10,000 others), and it shows up in its audience's living rooms two days later. The founder of the Students for Barack Obama Facebook group mined the site for references to Obama, and grew her organization into a 150,000-name list while barely leaving her campus in Maine. Where Daniel Ellsberg had to laboriously copy 7,000 pages of the Pentagon Papers, WikiLeaks can make enormously consequential buried documents available near-instantly.

Our online networks build on what sociologist Mark Granovetter called "the strength of weak ties." Older forms of community built on distinct local networks where people knew each other face-to-face, but where reaching out beyond those they saw day-to-day was harder. Our new tools make it easy to maintain far looser networks that we can continue to easily nurture. As Gideon Rosenblatt of the environmental group Groundwire points out, "these networks of weak ties can be put into action on a moment's notice, enabling online social change efforts to go viral at a speed and on a scale never previously possible." We take for granted our ability to link overlapping circles of friends and acquaintances in a manner until recently inconceivable.

For all its strengths, though, online activism has its limits. True, we can pass on information to friends who are on the fence about issues or haven't yet gotten involved. But most of what we do with the new tools reaches the unconvinced only fleetingly, and in a way that's often too peripheral to engage them. Because the threshold of response is so low, the representatives to whom we send our online petitions and automated emails can readily discount them. Even those who know us can become so saturated that they dread hearing from us. So while our forwarding, clicking, and networking can help us reach out and be heard, the Internet furthers social and political engagement only when it's used alongside other approaches. It's all-too-tempting to assume that because we've clicked on a petition on a given day, that's all the political involvement we need.

MoveOn's election efforts illustrate the challenge of persuading people to act offline. In 2006, the organization mobilized roughly 100,000 members to call Democratic-leaning voters who had a history of only showing up intermittently at the polls. Although follow-up studies suggested these calls made a major difference, just three percent of the organization's members participated. Most didn't make the leap from clicking and sending to picking up the phone or knocking on a door. In 2008, MoveOn created a massive phone bank where members called other members and encouraged them to participate--and managed to get a fifth of its members involved. But it took this older and more personal technology to do so. The organization and others continue to try to involve people face-to-face through efforts like their local MoveOn Councils and August 10 rallies against the corruption of American politics by money, but it will always take more than emails to get large number of people to participate.

We resist these more challenging forms of involvement because of vulnerability. We're invisible when we click, even if our name is attached to a letter or petition. If people disagree with us, we don't see their faces or hear their voices. When we call or knock on someone's door for a cause, we're far more exposed, not to mention ambivalent about intruding on private space. We're even more vulnerable when we raise contentious issues with people who know us. While our wonderful electronic tools can help people take non-threatening first steps toward engagement, proceeding beyond that is neither automatic nor inevitable.

The new technologies also help scatter our attention. We can waste endless days and nights clicking on Weblinks, texting or Tweeting about the minutiae of our lives, or being so focused on our Facebook friends that we have little time left for flesh-and-blood relationships, much less larger causes. Our Attention Deficient Disorder culture creates so many competing claims that it's now almost impossible to escape the noise, and harder still to distinguish important claims from trivial ones.

Given all this, we'd do well to remember that our new technologies work best when we combine them with more traditional mechanisms of engagement. The Obama campaign complemented new-media tools by establishing on-the-ground field offices in every corner of key states, recruiting and training local volunteers with deep community roots, following up again and again to get supporters to create the kinds of political conversations that actually changed minds. Similarly participants in recent immigration rallies texted, emailed and Tweeted to help bring their friends. But they also got encouragement through their churches, through Spanish-language radio, and through networks of more direct personal outreach. We're going to need all the public conversations we can create between now and November, and beyond.

When we create these more face-to-face connections, they can build sustaining community, which is no small thing in these frustrating times. For all the strengths of online engagement, people still need to gather together, eat, joke, flirt, tell their stories, attach names to faces, and ultimately build deeper levels of trust. And we need to keep reaching out in less glamorous ways. An activist in the University of Connecticut PIRG chapter described how she ignored endless email and Facebook solicitations for worthy causes. "Then someone actually called me. I was just so surprised because people almost don't do that anymore. It's easier to get involved when you're actually talking with another person."

If we assume that people will jump on our favorite cause just because they receive our communiqués and agree with us in principle, we underestimate the degree of inertia in our culture. For most people who are contemplating taking their initial steps into social involvement, a more intimate approach is often required, one that will put them at ease one question at a time, take their hesitations and uncertainties into account, and reassure them that the barriers they face are hardly unique. This more personal reach is key to enlisting new allies and to ensuring our political actions are visible enough to create a genuine public impact. That doesn't mean abandoning the astounding communicative tools we now have. But if we want to realize their potential, we're going to have to sooner or later step away from our screens.

Adapted from the wholly updated new edition of "Soul of a Citizen: Living with Conviction in Challenging Times" by Paul Rogat Loeb (St Martin's Press, publication date April 5, 2010, $16.99 paperback). With over 100,000 copies in print, "Soul" has become a classic guide to involvement in social change. Howard Zinn calls it "wonderful...rich with specific experience." Alice Walker says, "The voices Loeb finds demonstrate that courage can be another name for love." Bill McKibben calls it "a powerful inspiration to citizens acting for environmental sanity."