"Obama for America" is becoming "Organizing for Action."

The grassroots political network that made history in 2008 and 2012 is being morphed into a nonprofit advocacy group to help advance President Obama's agenda.

First Lady Michelle Obama made the announcement in a video message to supporters, calling the move "the next phase in our movement for change."

"For the past six years, you've done something so much bigger than elect a president. You've given ordinary people a place in our democratic process again," she says. "The relationships you made, the tools you built and the lessons you've learned have already begun to change our politics. And in the coming years they can change our country."

The group, which will be funded in part by corporate and individual donors, will exist independent of the Democratic National Committee, focusing primarily on progressive policy goals - Obama's goals - rather than campaign politics, Democratic officials said.

The transition is unprecedented for a presidential campaign apparatus. Never before has any been re-imagined in this way, nor has one survived for so long or remained as active in social media. Few have had such potential influence - or a donor list of 4 million strong - to bolster the work of a sitting president.

This weekend in Washington, 4,000 Obama campaign die-hards will huddle at the Hilton to chart the course forward. Obama's 2012 campaign manager and former chief of staff Jim Messina will serve as chairman of the new group, officials said.

The decision to keep OFA independent of the DNC isn't without some controversy.

The move has the potential to diminish the role and influence the national party, which traditionally inherits the remains of a presidential candidate's campaign infrastructure. It also complicates the path for the 2016 Democratic presidential nominee who would have to build a network from the ground up.

Tune in to the ABC News.com Live page on Monday morning starting at 9:30 a.m. EST for all-day live streaming video coverage of Inauguration 2013: Barack Obama. Live coverage will also be available on the ABC News iPad App and mobile devices.

But Democrats familiar with the new OFA said much of the following Obama amassed in 2008 and 2012 is "nontransferable," that it wasn't so much about loyalty to generic Democratic politics as it was to President Obama and his ideals. You could call it the "Obama brand" factor.

Others close to the new organization noted that the national party organization has never been structured to run issue-advocacy campaigns, and should focus instead on laying the groundwork for elections in 2014 and 2016.

The big questions to watch: will OFA be as potent in its next incarnation, and can it make history again?

Those answers could come soon enough, with the group poised to aggressively join the uphill fight for Obama's gun-control package.

While passage of any gun-control legislation would itself be a feat, so too, it seems, would be the active engagement of thousands of progressives over an issue that doesn't touch their pocketbooks or hinge on the personal popularity of a man who would be president.