Barack Obama is now the president of the United States, but his nearly two-year campaign for the office is far from dismantled.

Armed with a treasure trove of 13 million e-mail addresses, 4 million contributors and 2 million active volunteers, the Obama team -- regarded as one of the most powerful grassroots organizations ever assembled -- is transforming its structure into a lobbying and volunteer fixture that will continue to benefit the president, perhaps well into a 2012 re-election bid.

Both Democratic and Republican strategists say that capitalizing on this massive database can reap many rewards -- but keeping a campaign intact beyond an election wades into some uncharted waters.

Some people are raising legal questions about how the group will function, how it will lobby members of Congress on Obama's behalf and how it will work in coordination with the Democratic National Committee. Others ask whether it can satisfy both the liberal blogosphere and more moderate and conservative Democrats.

Obama announced the formation of Organizing for America, dubbed "Obama 2.0" by insiders, on YouTube on Jan. 17, just three days before he took office.

A December memo sent to some supporters indicated that Organizing for America would promote "legislative issue organizing to support President-elect Obama's agenda, electoral organizing, civic engagement" and communication between the Obama administration and grassroots supporters. The group plans to expand its grassroots organization, "directly lobby members of Congress and other elected officials," and "work to win local elections."

"This is a powerful tool that they have if they use it right," said Massie Ritsch, communications director of the Center for Responsive Politics.

He said it can be a political party, a lobbying organization, a grassroots mobilization effort, and a re-election campaign in waiting, able to "start up its engines" very quickly for 2012.

But Obama's opponents have many questions about Organizing for America. One Republican strategist said legal problems could arise, depending on how it's constructed. The source of funding is significant, the strategist said. If the Democratic National Committee is involved, as planned, and is spending the money on lobbying, does it violate its 527 status? If the organization's fundraising is separate from the DNC and viewed as part of the Obama campaign, do monies count against the limits on Obama's 2012 race?

It's also unclear who in the White House would coordinate with the group. Antideficiency laws would prevent a White House official from asking an organization to spend money for direct lobbying of members of Congress, the Republican strategist noted.

Organizing for America's exact relationship with the DNC is still undefined, but a DNC source familiar with the group's formation described it as a "special project of the DNC" that will be "housed within the DNC." Right now, video announcements about Organizing for America have been posted on both BarackObama.com and the DNC site, Democrats.org.

Reporting by the LA Times indicated the annual budget for the organization could be as much as $75 million. But the DNC source said that staffing and budget decisions are still being made, and that it's not clear exactly where the money will come from or how much it will be. A timeline for official launch has also not been determined, said the source.

Presuming everything is kept within the limits of the law, the Republicans have reason to be worried. The Obama campaign's grassroots organization was "very impressive" compared to the GOP's, the Republican strategist said, and Obama 2.0 "has the ability to be highly effective."

But the transition from a candidate's campaign organization to a legislative lobbying group may not be a seamless one. "Re-electing Obama is one thing, and nudging members of Congress to back Obama's programs is another," Larry Sabato, director of the Center for Politics at the University of Virginia, said in an e-mail.

"It's possible that Democratic members of Congress will resent the pressure coming from their own president. The Blue Dogs will be special targets, one supposes," he said, referring to a group of conservative Democrats in Congress. "But to keep their districts safe, the Blue Dogs probably have to vote their own way from time to time."

The organization also must be careful not to get "too closely aligned with the Democratic Party," said Ritsch. "Many of the people who signed up wouldn't consider themselves to be ardent Democrats or even Democrats at all," he said.

And then there are Obama's left-wing supporters. Some liberal blogs have already expressed anger and disappointment with the operation of the post-campaign structure. Early this month, about 100,000 visitors to the transition site Change.gov voted on questions they wanted answered by Obama. In a concerted effort, liberal bloggers promoted a question about appointing a special prosecutor to investigate the Bush administration, and the question topped about 76,000 other queries. The Obama team ignored the question until mainstream media outlets brought it up.

One blogger at Crooked Timber wrote:

"Under normal politics, they might be able to sweep this under the rug ... But the creation of an open architecture, where others can bring inconvenient issues up -- and very likely keep on bringing them up -- makes it substantially more difficult for them to maintain control of the conversation." In some cases, "the volunteer movement going to be [sic] more of a bully than a bully pulpit, setting the agenda rather than serving as a glorified force-multiplier for things that the president would like to see happen."

With this in mind, some wonder if Organizing for America will be beneficial to Democrats in the long run, especially once Obama leaves office.

"This plan for the future of the Obama political operation is something of a double-edged sword," a blogger wrote on both the Future Majority and Daily Kos Web sites.

"It might allow for fantastic legislative accomplishments (assuming you agree with all of Obama's policy prescriptions), but it could leave a seriously weakened party structure in its wake once Obama is no longer in charge. And if it weakens the state parties without committing resources downballot, it could actually cause the Democratic Party to atrophy at the local level."

Regardless, the Democrats appear to be in better shape than their counterparts for the next few years. Obama's "50-state" strategy was successful in the fall, and Republicans are now making plans to emulate it. Republicans learned in 2008 that "any state can be a battle state," said a GOP official.

But the change won't come soon enough to help the GOP significantly in 2010, Sabato says. The Republicans are "years behind the Democrats," he said.