Ron Paul said he's the only candidate who can challenge Mitt Romney after his second-place showing in New Hampshire.

"We have had a victory for the cause of liberty tonight," Paul told supporters, who cheered him on at a rowdy celebration as networks projected he'd be the runner-up in the New Hampshire primary. 

"The intellectual revolution that's going on now to restore liberty in this country is ongoing. There is no way that they are going to stop the momentum that we have started. That is the victory that you have brought about," Paul said.

Romney was projected as the winner of the first-in-the-nation presidential primary, with 38 percent of the vote and nearly 50 percent of precincts reporting. Paul had 23 percent.

Paul joked in his victory speech that he was "nibbling at [Mitt Romney's] heels." He congratulated Romney for winning the state and said he had called his GOP rival.

Paul finished third in the Iowa caucuses, meaning he's had the best results in the first two contests than anyone but Romney, who won in both states. Still, most political observers don't think the libertarian candidate can really win the GOP fight given his anti-establishment views, particularly on foreign policy.

Paul turned his speech into a passionate campaign pitch for his platform's libertarian principles. 

"I really get excited when I see young people saying [freedom] is a good idea," Paul said.

"I sort of have to chuckle when they describe you and me as dangerous," he continued, speaking to a crowd of supporters. "That is one thing they are telling the truth because we are dangerous to the status quo in this country."

Paul also took a shot at the New Hampshire Union-Leader, which endorsed Newt Gingrich, who was still battling neck-and-neck with Rick Santorum for fourth place in the vote when Paul spoke.

"I want to thank the Union Leader for not endorsing me," Paul added.