PHILADELPHIA, Nov. 10 — From posting video on YouTube to enlisting friends through Facebook, all of the presidential candidates are looking for ways to harness the Internet. In the case of Ron Paul, the Internet has harnessed him.

Mr. Paul, a 10-term Texas congressman who is seeking the Republican presidential nomination, came into the campaign with a conservative platform: a return to the gold standard, abolition of the I.R.S., a literal view of the Constitution. His campaign was bare bones. Then he started appearing in debates. His emphatic presence and fierce opposition to the war in Iraq set him apart from his fellow Republicans. Setting him even farther apart were ideas like blaming American foreign policy for the attacks of 9/11 and abolishing the Federal Reserve.

If his campaign had taken place in the pre-Internet era, it might have gone the way of his 1988 Libertarian campaign for president, as a footnote to history. But because of the Internet’s low-cost ability to connect grass-roots supporters with one another — in this case, largely iconoclastic white men — Mr. Paul’s once-solo quest has taken on a life of its own. It is evolving from a figment of cyberspace into a traditional campaign, with yard signs, direct mail and old-fashioned rallies, like one here on Saturday attended by a few thousand people under cold, gray skies. Mr. Paul said it was his biggest rally so far. He said it proved his campaign was more than “a few spammers” and called it a “gigantic opportunity” to establish credibility.

How much the Paul campaign had snowballed on the Internet became evident last week when supporters independent of the campaign raised $4 million online and an additional $200,000 over the phone in a single day, a record among this year’s Republican candidates. There is even talk that Mr. Paul could influence the primary in New Hampshire, where he could draw votes from Senator John McCain of Arizona, who is trying to revive the independent persona that helped him win the state’s primary in 2000.