Will the White House Web site work as a social network?

A more engaging site, Gensemer says, will help Obama cultivate groups of "superactivists"—the tens of thousands of especially motivated people who, during the campaign, took time off from work and relocated to other states in order to volunteer full-time. Let's imagine that Obama's ambitious health care plan runs into trouble in Congress. The social network might help him identify the few hundred or few thousand health care activists in key congressional districts who agree with his proposals. In the same way that Facebook lets you plan a lavish birthday dinner for yourself, the White House Web site would let activists hold gatherings to lobby their legislators on Obama's behalf. "If a congressman goes home and sees a town hall meeting with 1,000 people in their district, that matters," Gennsemer says.

Is this a realistic scenario? "Congress is the great shock absorber of American politics. Movements go there to die," says Micah Sifry, co-founder of an annual technology and politics conference called the Personal Democracy Forum. Organized interests—the health care industry, say—wield influence in this environment because they've got the money and the patience to be there every day and keep pressing their agenda. At its best, says Sifry, the social network will help Obama develop a counterweight to those groups. "The White House has always had the bully pulpit to go over the heads of Congress through the mass media," he says. "What Obama now has is the ability to go between the legs of members of Congress."

But that presumes that all of Obama's social-networking friends will support his agenda—and what if that's not the case? What happens when conservatives flock to the White House Web site to post nasty comments opposing Obama's stem-cell policy or if Sean Hannity urges his audience to use the site's tools to plan gatherings protesting Obama's tax plan? Even Obama's supporters are likely to disagree with him from time to time; already, there are online petitions and Facebook groups calling on him to skip over Larry Summers and Robert F. Kennedy Jr. for Cabinet positions. The opposition might be especially hairy during periods of national emergency—if Obama decides to launch military action, would the White House Web site fill up with comments showing that the country is not fully behind him?

During the campaign, we saw one vivid example of how Obama might handle online protests of his policies—he'll let them go on. In June, the senator announced that he had switched positions on the Foreign Intelligence Surveillance Act. He decided to vote for an updated version of the bill even though it offered immunity to telecom companies that had worked with the Bush administration's warrantless wiretapping program, a measure that many of his supporters vehemently opposed.

Protestors immediately took to the campaign's site; a group urging Obama to reject the billswelled to more than 20,000 members, making it by far the site's largest. Obama didn't change his mind on the eavesdropping bill. But neither did the campaign take any steps to shut down the anti-FISA group, and shortly before voting for the bill, Obama posted a lengthy note to the group explaining why he'd voted for the bill, and his policy staff answered hundreds of comments from the group explaining the nuances of the senator's position.

Alan Rosenblatt, the associate director of online advocacy for the Center for American Progress Action Fund, says that if Obama does the same thing while in office, he might be able to blunt some of the inevitable criticism of his proposals. "If there's a level of back-and-forth, it creates a sense of democracy," Rosenblatt says—and that sense of democracy ends up serving the candidate well. The FISA protest took place during a key moment in the Obama campaign—just after he'd locked up the nomination, at a time when many volunteers were deciding how much work to do for the campaign. I called up Chrisi West, a 29-year-old Obama supporter who opposed his position on FISA but who, nevertheless, went on to become one of the campaign's most active supporters in her home state of Virginia. West told me that Obama's response on the eavesdropping bill helped convince her that the online community wasn't incidental to Obama—that he actually respected what people thought of his positions. That kind of openness only pushed people to work harder, West said, and when he takes office, "we'll all be ready to jump in when we're needed."