ANKENY, Iowa » It was four years ago that Ross Witt, a soft-spoken electrical engineer at John Deere, overcame his natural discomfort with knocking on hundreds of his neighbors’ doors during dinnertime as a precinct coordinator for Ron Paul’s campaign.

But when Paul dropped out of the national race in June 2008, Witt did not stop, because, in a sense, neither did Paul: Witt and many other supporters here joined the Iowa branch of an independent political group Paul established after the race. They carried on his libertarian message, and picked local organizers. And when the Texas congressman announced he was running for president this year, Witt and others jumped back onto his campaign, a force more motivated and efficient than before.

Alone among the Republican field, Paul has a built-in network from 2008 that gives him a decisive organizational edge. Iowa Republicans say that advantage is an important reason some polls show him within striking distance of pulling off a victory in the Jan. 3 caucuses, with a battle-tested ground game poised to take advantage of a lack of passion for the rest of the candidates, a stark contrast to 2008 when evangelicals rallied around Mike Huckabee.

"This isn’t a year-and-a-half campaign," Craig Robinson, a former Iowa Republican party political director during the caucuses four years ago, said of Paul’s organization. "This is a five-year campaign."

Paul’s support comes from incredibly loyal and somewhat diverse backers, like college students attracted to his anti-war stance and his desire to end the federal ban on marijuana and other drugs, conservative populists suspicious of Wall Street who cheer his criticism of the Federal Reserve and Tea Party activists who embrace his small government credo.

His consistent positions over the years also set him apart from other candidates bedeviled by charges of flip-flopping. But they also could undermine him, as his debate performance Thursday highlighted a rigid anti-war stance out of sync with many Republicans.

Paul’s campaign has grown more adaptable. Hundreds of college students are being recruited to travel on their own nickel to Iowa and New Hampshire, where the campaign will pay their food, housing and gas while they knock on doors and make phone calls in the run-up to the two contests. Paul backers hope the effort blunts the unfortunate timing of the Iowa caucuses during Christmas break, which could undermine turnout among his fervent student base.

At a recent University of Iowa rally, that enthusiasm was on display. Paul praised the students, saying young people "seem to understand what liberty is all about so much better than some of those individuals that have been in Washington way too long, and they don’t have the vaguest idea what liberty is all about!"

The campaign developed an Internet-based phone-banking system that allows people around the country to make calls to Iowans from home using scripts tailored to identify supporters. It seems to be working: A poll by The /CBS News this month foundB that 60 percent of likely Republican caucus-goers said they had been contacted by the Paul campaign, the highest rate of any candidate, and about double that of Newt Gingrich. The true believers have also been coached not to be rude or dismissive to those who do not embrace the message, an issue during the last campaign.

"We don’t want volunteers arguing with them," said Dimitri Kesari, deputy national campaign manager.

And Paul’s biting commercials have been running relentlessly on Iowa stations, winning raves and tearing into Gingrich, now his main rival here.

Even before all that started, Paul had a tactical edge, Republican activists say: A lot of his infrastructure stayed intact during the interim through his newly-founded group, Campaign For Liberty. One senior Iowa Republican official described it "as a shadow campaign in waiting."

The group became a bridge between campaigns, they said, keeping important supporters primed, a boost in a state where on-the-ground organization means everything.

"It became the continuous organizing force during the off years for the Paul message, sponsoring events when Paul showed up, and continuing to reach people who shared his views," said Doug Gross, the 2002 Republican nominee for governor and Mitt Romney’s 2008 state chairman.

While polls suggest Paul may do well in Iowa and New Hampshire, the question remains whether he will be anything more than a spoiler, a candidate helping prolong what could be a drawn-out nominating battle.

In Iowa, however, his "ground game" could pack a punch and elevate his candidacy nationally. Unlike primary states where voters disappear behind a curtain to pull a lever, Iowa’s Republicans (and independents and Democrats willing to join the GOP for a day) will gather in about 1,800 caucuses to vote, sometimes by a show of hands. It is a social event, where neighbors lobby each other, making enthusiastic advocates like Witt a candidate’s most valuable currency.

On caucus night, Witt will lobby his neighbors all the way up to the voting, including a short speech. He will also run the caucus, as the precinct GOP chairman. He said many other Paul activists — perhaps even hundreds — are now also on hiatus from Paul’s independent group to play a role in the campaign.

Paul supporters say the independent group has never done anything to specifically benefit Paul that could run afoul of its status as a tax-exempt 50104 organization. Senior campaign officials play down the group’s influence, suggesting that not many people have crossed over.

"I don’t think it is very high," said Drew Ivers, Paul’s state chairman, who suspended his involvement with the group when he went back to the campaign, as he said others also did. He and Paul’s two state co-chairmen — along with two other Paul supporters — now comprise five of 17 members on the state GOP central committee, a formidable presence in the party.

Other campaigns question whether Paul’s surge is all that it seems, arguing that Democrats and independents who respond favorably in polls are less likely to trudge to a GOP caucus on a cold night.

"A lot of his supporters live in basements," scoffed one official at a rival campaign, who nevertheless predicted Paul will finish well above his fifth-place 2008 showing.

The official added what is fast becoming cliche: that bad caucus-day weather favors Paul’s highly-motivated supporters. "He’s praying for a blizzard."