NEW YORK — Transition officials call it Obama 2.0 — an ambitious effort to transform the president-elect’s vast Web operation and database of supporters into a modern new tool to accomplish his goals in the White House.

If it works, the new president could have an unprecedented ability to appeal for help from millions of Americans who already favor his ideas, bypassing the news media to pressure Congress.

‘‘He’s built the largest network anyone has ever seen in politics, and congressional Republicans are clueless about the communications shift that has happened,’’ Democratic strategist Joe Trippi proclaims. The results, he says, ‘‘will be amazing to watch.’’

Republicans say they’ll be watching for White House Web outreach that appears overly political.

‘‘Hopefully, Obama will be a president for all Americans, not just the political supporters on his e-mail list,’’ said Republican National Committee spokesman Alex Conant.

Obama’s people know they’ll have to extend their reach. During his 21-month campaign, Obama built a list of 3.1 million contributors and over 10 million supporters who helped power his victories over Democratic rival Hillary Rodham Clinton and Republican John McCain. In addition to helping raise a staggering $660 million, the campaign’s Web effort reinforced his message and themes, responded to political attacks and created volunteer social networks that served as the basis for his field operation.

Obama’s team is determining how best to convert his army of online activists into a viral lobbying and communications machine. Staffers are reluctant to discuss specifics, but Obama clearly is poised to become the first truly ‘‘wired’’ president of the digital age.

For legal and privacy reasons, Obama’s campaign list must be kept separate from White House operations. Aides are figuring out if that list should be run through the Democratic National Committee or as a freestanding political entity that will eventually become his 2012 re-election committee.

But transition officials have already begun a new digital outreach effort, based on the campaign model, aimed at supporters and others interested in being connected to the activities of the Obama White House.

The transition operation has a new Web site, www.change.gov, designed for anyone who wants to post a message of congratulations, offer suggestions for the new administration or apply for a government job. People are invited to submit their names and e-mail addresses, with the goal of creating a new list for the president-elect to tap when he wants to communicate directly about a program he’s promoting or seek help urging members of Congress to support legislation he’s proposed.

‘‘Just imagine what happens when a congressman comes back to his district and 500 people are lined up for his town hall meeting because they got an e-mail from Obama urging them to attend,’’ said Thomas Gensemer, managing partner of Blue State Digital which designed Obama’s campaign Web site and change.gov.

Gensemer said to be most effective, Obama needs to make clear that his Web outreach efforts aren’t directed only at partisan Democrats.

‘‘If you’re looking to build a community as president, the net needs to be cast a little broader,’’ Gensemer said. ‘‘If you want to bring Republicans along, you use the Web to say, ’Work with me. Help me cut through the partisan rancor.’’’