More profoundly, while many people think that President-elect Obama is a gift to the Democratic Party, he could actually hasten its demise. Political parties supply brand, ground troops, money and relationships, all things that Mr. Obama already owns.

And his relationships are not the just traditional ties of Democrats  teachers’ unions, party faithful and Hollywood moneybags  but a network of supporters who used a distributed model of phone banking to organize and get out the vote, helped raise a record-breaking $600 million, and created all manner of media clips that were viewed millions of times. It was an online movement that begot offline behavior, including producing youth voter turnout that may have supplied the margin of victory.

“Thomas Jefferson used newspapers to win the presidency, F.D.R. used radio to change the way he governed, J.F.K. was the first president to understand television, and Howard Dean saw the value of the Web for raising money,” said Ranjit Mathoda, a lawyer and money manager who blogs at Mathoda.com. “But Senator Barack Obama understood that you could use the Web to lower the cost of building a political brand, create a sense of connection and engagement, and dispense with the command and control method of governing to allow people to self-organize to do the work.”

All of the Obama supporters who traded their personal information for a ticket to a rally or an e-mail alert about the vice presidential choice, or opted in on Facebook or MyBarackObama can now be mass e-mailed at a cost of close to zero. And instead of the constant polling that has been a motor of presidential governance, an Obama White House can use the Web to measure voter attitudes.

“When you think about it, a campaign is a start-up business,” Mr. Mathoda said. “Other than his speech in 2004 at the convention and his two books, Mr. Obama had very little in terms of brand to begin with, and he was up against Senator Clinton, who had all the traditional sources of power, and then Senator McCain. But he had the right people and the right idea to take them on. When you think about it, it was like he was going up against Google and Yahoo. And he won.”

There is tremendous power in opening citizen access to government  think of how much good will and support Mayor Michael Bloomberg garnered by coming up with 311, a one-stop phone number for New Yorkers who had a problem.

But now Senator Obama’s 20-month conversation with the electorate enters a new phase. There is sense of ownership, a kind of possessive entitlement, on the part of the people who worked to elect him. The shorthand for his organizing Web site, “MyBO,” says it all.