Barely finished with her victory speech after the Pennsylvania Democratic primary Tuesday night, Hillary Clinton racked up nearly $2.5 million in new donations, her campaign boasted - the latest evidence that the most fertile ground for waging war in this election may be the Internet.

"There are more Americans using the Internet in a more significant way than ever before," said Simon Rosenberg, president of the Democratic think tank NDN. "The country's changing. We're changing. Politics are changing."

And fast.

Back in 2003-04, Howard Dean's presidential campaign was relatively alone in its embrace of the Internet as a tool for political campaigning, turning supporters into partners in his fight for the Democratic nomination.

One term later, all three major presidential candidates and everyone from hip-hop artist will.i.am to actor Jack Nicholson seem to understand the importance of the Net and its advanced tools, such as YouTube, social networks and blogs, now entrenched in American culture.

"There are people who watched in 2004 and laughed, as if people on the Internet were somehow different than the American people," said Joe Trippi, one of the masterminds behind Dean's campaign. "But the last time I checked, there are almost 80 million Americans on the Internet. It's not like some cult somewhere; it's the American people."

Clinton and Republican Sen. John McCain have a strong Web presence, but no one has felt the importance of the grassroots support of the Net more than Clinton's primary opponent, Sen. Barack Obama, who has more than 1.2 million donors and has raised a reported $142.5 million in the first quarter of 2008 alone - $50 million more than Clinton.

Eight-year-old Simon Shankweiler is just one of the Obama faithful who is helping the candidate shatter fund-raising records and organize supporters nationwide.

In January, the Swarthmore native, a soft-spoken Harry Potter look-alike, posted a video of himself drawing a red, white and blue donkey for Obama. Since then, the video has received 1,600 hits on YouTube (as of this week), and the illustration has culled more than $90 in button and T-shirt sales online for the Obama campaign. Simon also opened a refreshment stand to sell hot "coco-bama" (and, later, "obama-ade"), raising $850 more to date.

With help from his mother, Simon also has turned his little stand into a national movement by using Internet listservs and Obama's social network, my.barackobama.com, to cultivate an association of supporters to push refreshments in more than 20 states.

Although $940 is only a sliver of the tens of millions Obama raised in the same period, every little bit counts - especially when supporters are using the Net to motivate other people.

"I think it's empowering," Simon's mother, Carrie, said. "The Internet gave us a voice and helped us put our stuff out there. It helped me tell the entire planet about this little kid who gets it."

And that's the real power of cyberspace. The true beauty of the Net lies in its ability to make people feel as if they aren't meaningless cogs, but rather vitally connected to interactive campaigns.

"It allows millions and millions to be involved," Rosenberg said. "I think Internet politics is . . . helping to renew democracy by allowing citizens to play a role, more so than ever before."

Obama is outdoing Clinton on Twitter, a free social-networking site (22,000 followers to her 2,185). His Web site was visited by twice as many people as Clinton's during the first quarter of 2008.

However, Clinton's Net presence is not insignificant.

Visitors to Clinton's site have a higher average stay per visit in 2008, compared with Obama's, and she's even created her own YouTube viral phenomenon (a Sopranos- finale spoof with her husband). Clinton has also begun to embrace user-generated support videos on her site, "The Hillary I Know" (thehillaryiknow.com).

"It's a perception-vs.-reality thing," said Peter Daou, Clinton's Internet director. "There are perceptions that the senator doesn't have support in the blogosphere, but if you look into it, there is a lot of support for her."

Alex Lasky and other supporters created the independent support site "Hillary Speaks for Me" (hillaryspeaksforme.com), which streams a video of clips sent in from Clinton supporters.

Although Rosenberg gives the Clinton campaign credit for "tremendous strides," he said the former first lady has been hurt by her late embrace of the Net's participatory nature.

"The Clinton campaign never really believed it was a partnership until recently," Rosenberg said. "It was all about her, not about us."

Trippi is more severe in his criticism, calling the Clinton campaign's inability to realize campaign structuring had changed "the biggest blunder I've ever seen in 30 years of doing this."

Regardless of how experts assess the situation on the Democratic side, most agree that the hoopla has registered far less with the GOP. Even though McCain had his best fund-raising month in March, with $15.4 million, and has all the Net trinkets his counterparts do, critics have cited his Internet presence as comparatively weak. Traffic to his site (half that received by Clinton and a quarter of Obama's) and his Twitter following (295) rank far behind those of the other candidates.

"The Democrats are light-years ahead of the Republicans, mostly because George Bush did a top-down in 2004," Trippi said. "No one was building the Republican following."

However, Julie Germany, deputy director of the Institute for Politics, Democracy & the Internet, suggests the reason for the low numbers is not incompetence, but the simple fact that McCain isn't embroiled in a nominating war as are the Democrats.

"There's this myth out there that Republicans don't understand the Internet, and that's just wrong," said Germany. "They understand it and do use it, but it comes down to strategy and knowing who your supporters are."

What is obvious, experts say, is that Net campaigning is permanent and will be central in future political strategies.

"No matter what numbers Obama puts up in volunteers or money, in 2012 or 2016 someone's going to make his numbers look just as ridiculous as he makes the Dean numbers look today," Trippi said. "By then that many more Americans will be online, and the tools will be even better."