Photo Credit: Obama CampaignBen Rhodes, a foreign policy adviser to Barack Obama, and Danielle Gray, deputy policy director for the Obama campaign.

He responded. While most Americans settled into a relaxed Independence Day weekend, Barack Obama tried to quiet mounting criticism from supporters over his decision to back a new White House spying bill. In an unprecedented letter released on the afternoon of July 3, Obama addressed the thousands of supporters who organized a large protest on his social networking portal.

Noting that he expected to take his “lumps” and “be held accountable,” Obama respectfully defended his surveillance reversal. While maintaining that immunizing companies accused of illegal spying undermines deterrence and “accountability for past abuses,” Obama said he now backs legislation granting the right to give immunity (and other executive powers) because it provides a “real mechanism for accountability” via future investigations. The explanation ran 852 words–more than double the length of his original statement announcing support for the spying bill on June 20–and then campaign policy aides continued the discussion for over an hour with visitors on Obama’s site (pictured at right). The unusual exchange sparked an intense debate over the weekend, as activists and bloggers questioned whether it heralded a more interactive political era, or a reminder that double talk can spread on any medium.

On Sunday night, the protest group released its official reply, collaboratively edited through a wiki and representing some of the 19,000 members. It pressed Obama to take his fight against immunity to the Senate floor this week. Since Obama’s letter said he still wanted to “strike” immunity from the bill, the group urged him to take charge:

We ask that you back up your words with action by addressing your constituents on the floor of the Senate with the same oratorical power you used in Philadelphia to lay out your vision of a ‘More Perfect Union.’ The American people have just as much right to know of the dangerous precedent this Congress would be setting by granting retroactive immunity to [companies that spied] on law-abiding citizens as we did to relearn of segregation and Jim Crow. The arm of government oppression reaches far and wide, Senator, and we must beat it back on whatever front we find it.

The Senate begins debating the spying bill again on Tuesday. Obama arrives in Washington that day to address a Hispanic convention.

The protest group has not only become a huge force on Obama’s site–it is now double the size of any other user-created group and its traffic slowed the campaign’s server last week–it has also swiftly asserted itself in the broader spying debate. Organizers have been covered and quoted repeatedly in the mainstream media, including a New York Times profile of founder Mike Stark, tapping the interest in online organizing to amplify a civil liberties message. The group’s wiki even includes a “proposed strategy” to “fan the flames of coverage by making the novel outreach approach a story in its own right,” levering media attention to recruit more members for lobbying Congress. Over the weekend, it began spinning off local networks to target individual senators through a “ fifty state strategy.” Now there are Facebook groups for constituents to pressure senators McCain, Feinstein, Klobachar, Coleman and Alexander–along with a page for “Wisconsinites” to “thank” Senator Feingold for defending civil liberties. The group decided to focus on other senators after discussing how to broaden the effort beyond Obama. Over 3,500 members converse through an e-mail listserve on the campaign’s social networking platform, with hundreds of messages a day. In fact, the group has begun moderating participation to limit topics and exclude certain tactics, such as attempts by activists to halt campaign fundraising in retribution for Obama’s position on spying.

By simultaneously growing its membership, mission and ambition, the spying group exhibits the characteristics of a successful net movement. MoveOn began with the single objective of fighting Clinton’s impeachment, but evolved to tackle other issues that resonated with its members. The protest against the spying bill began last month by urging Obama to change his vote. After quickly drawing him (and his senior staff) into a dialogue, however, it is nimbly shifting its focus to Obama’s role in the immunity floor fight–an easier request on common ground–while launching campaigns to target senators with constituents recruited through MyBarackObama.com. Even if the Democratic Congress completes its capitulation on surveillance policy, the anti-spying group will still be the largest organizing network on Obama’s site. With 6,000 more activists than the top-down “Action Wire” group, which the campaign created for official pushback, the group might even function as a supportive but aggressive counterweight to the campaign’s traditional message. If Obama is not confronting McCain on other constitutional issues, for example, members could organize media or social network efforts to do it for him. If the campaign is not correcting the media for distorting factual statements by Gen. Wesley Clark, the members could rally a truth squad overnight.

Obama excelled by appealing to the public appetite for movement politics, rather than typical campaigns. And unlike campaigns, movements are animated by ideas, policies and values–not blind allegiance to a single person. If Obama is lucky, he will continue to benefit from these energized, sophisticated activists who support his candidacy while they press his hand, and use his campaign platform to mobilize turnout while organizing causes beyond his election. The spy group’s open letter reminded Obama of this collective dynamic. “As you have said time and again Senator, ‘we are the ones we have been waiting for,’ and we are here, working to bring about real change in Washington.”