The contests between Senators Clinton and Obama in New Hampshire, Iowa, and Nevada in 2008 will determine how new this political era is.

Ms. Clinton is already ahead by at least 20 points in most polls. She has captured an early wave of institutional support. She has the bulk of the collective fund-raising and field base with her. Mr. Obama, meanwhile, is positioning himself as the darling of the loosely connected politically liberal Web sites, the NetRoots. His campaign hinges on whether the uncharted power of the social networking sites on the Internet, such as MySpace and Facebook.com, can offset the organizational advantages of his strongest opponent.

Right now nobody knows if Mr. Obama’s presence on social networking sites will amount to anything. And just as Ms. Clinton followed John Edwards and Mr. Obama onto the Web with her campaign announcement, her campaign team is nimble and able to shift more resources online if need be.

Democrats in Massachusetts draw an analogy between the candidacies of Mr. Obama and Deval Patrick, who in the space of two years transformed himself from a political nonentity to a political powerhouse and is now the governor. While other candidates, such as Tom Reilly, the former attorney general of Massachusetts, captured institutional support, Mr. Patrick quietly built an underground political network that overwhelmingly propelled him to the nomination. It wasn’t the only thing that helped Mr. Patrick win the nomination — Mr. Reilly committed a series of missteps that helped torpedo his front-running effort. Ms. Clinton, though, surely will be stronger than Mr. Reilly. Still, Mr. Patrick may have perfected the road map for Mr. Obama to follow.

“I’ll tell you something about Barack Obama that the media has not picked up on. He has got a very, very powerful presence on Facebook, on MySpace, on a lot of these sort of below the radar social networking sites on the internet,” David Kravitz, a co-founder of the Massachusetts Democratic Web site, BlueMass-Group, bluemassgroup.com, speaking on New England Cable News, said. Mr. Kravitz’s site endorsed Mr. Patrick in August 2006, and ultimately became one of the many forces driving him to victory. “It’s way ahead of any other candidate.”

As of yesterday, a Facebook group founded by Farouk Olu Aregbe and called “Barack Obama (One Million Strong for Barack)” had garnered 259,647 members. By contrast, the largest group I could find in favor of Ms. Clinton was “Hillary Clinton for President — One Million Strong.” It had 3,251 members.

So-called social networking sites are different from blogs, which captured press attention back in 2004. Blogs are splashy and high profile. Blogs are the tabloids, oped pages, and newscasts of the Internet world, whereas networking sites are the direct mail, the sign-holders, and the door-knockers. A blog can chew up a political opponent and get negative information out there. A networking site, in theory, can move bodies.

The size and rapid growth of the pro-Obama site was causing a stir on the Web. A Facebook co-founder, Chris Hughes, said as much to the Raw Story, rawstory.com, a liberal newsgathering site. Mr. Hughes called the surge behind Mr. Obama “unprecedented.” Mr. Obama’s Web efforts will mirror those that made Governor Dean of Vermont a threat to win the nomination in 2004, that allowed Ned Lamont to capture the Connecticut Democratic Senate nomination in 2006, and that helped win for Mr. Patrick the governor’s office in Massachusetts. Of these, the only ultimate winner was Mr. Patrick. One distinguishing factor for Mr. Patrick was his campaign’s ability to transfer Web presence to old-fashioned grassroots boots on the ground. He used his Web efforts to get the names of supporters, direct them to caucuses and events, and, ultimately, to the polling place on Election Day. The scary thing for supporters of Mr. Obama is the scope and scale of institutional knowledge of Ms. Clinton’s campaign. Her husband inherited the primary-winning machine of field operatives that Michael Dukakis built in 1988. He perfected it and gave it to Vice President Gore in 2000. Much the same operation assisted John Kerry, who, while he lost in the general election, was able to pull off a surprise win in 2004 in Iowa. Mr. Kerry’s operatives mastered the logistical intricacies of the Iowa caucuses in 2004 and convinced voters to “Date Dean” but “Marry Kerry.”

The buzz and hype right now reverberate around the Web. But traditional voters still reside in the dense neighborhoods in and around Manchester, they congregate in the meeting halls of Iowa, and they belong to the service unions in Las Vegas. These people are out working at jobs and are not necessarily on the Web much of the day. The 2008 election will show how many of these voters will be reached despite the allure of newfangled technology.

Mr. Gitell (gitell.com) is a contributing editor of The New York Sun.