DES MOINES, Iowa -- Ron Paul, once seen as a fringe candidate and a nuisance to the establishment, is shaping the 2012 Republican primary by giving voice to the party's libertarian wing and reflecting frustration with the United States' international entanglements.

The Texas congressman placed second in a key early test vote Saturday, coming within 152 votes of winning the first significant balloting of the Republican nominating contest. And his organizational strength and retooled focus on social issues set him up to be a serious player.

Four years ago, Paul sought the GOP nomination while talking about economic policy, liberty and the Federal Reserve. Since then, the tea party has risen and seized on those issues, and some regard Paul as one of the movement's godfathers.

Still, he finds himself outside the bounds of traditional Republicans. His opposition to the wars in Iraq and Afghanistan defines him as a dove. His skepticism toward the Federal Reserve has spooked Wall Street. And his libertarian views on gay rights draw the ire of social conservatives.

Paul also proves a reliable foil for Democrats.

"In previous presidential campaigns, we might have chalked extreme fringe-type candidates like Michele Bachmann and Ron Paul as an anomaly, (and) the Ames straw poll didn't mean as much," said Rep. Debbie Wasserman Schultz of Florida, chairwoman of the Democratic National Committee.

"But we're looking at the core of the Republican Party now. The heart of the Republican Party is the extreme right wing," she told CNN.