MASON CITY, Iowa — Republican presidential candidate Ron Paul said Monday his path to the party's nomination was unclear without a strong performance in Iowa's leadoff caucuses.
"It will be a real challenge. There's no doubt," Paul told The Associated Press aboard a charter jet on a five-city sprint on the eve of the leadoff caucuses. "We've invested a lot of time and money in doing well here."
Paul's campaign was preparing to criticize rival Rick Santorum, a former Pennsylvania senator who has risen sharply to the top tier in the past week after gaining traction with Iowa's divided social conservatives.
Paul, among the leaders in Iowa polls since last month, returned to the state after two days at home in Texas. His five rivals for the caucuses crisscrossed Iowa over the holiday weekend.
Campaigning with a son, Sen. Rand Paul, R-Ky., the libertarian-leaning Texan defended the 48-hour break in campaigning, even as final polls published at the end of last week showed more than a third of likely caucus-goers undecided or willing to change their mind before the caucuses.
Paul expressed faith in his Iowa organization, a far more structured network than his 2008 Iowa campaign that helped him place fifth in Iowa four years ago.
"I don't want to sound over-confident, but I am confident in our organization," he said, arguing that other candidates were still scrambling to shore up their supporters. Paul has a robust staff in New Hampshire, and he began running ads in South Carolina, where the South's first primary is scheduled for Jan. 21.
Still, Paul was waiting until Friday to head to New Hampshire, where he is rising but far behind former Massachusetts Gov. Mitt Romney in polls.
Paul's confidence was buoyed Monday as big crowds packed with younger supporters met him in Des Moines and cities in eastern and northern Iowa.
"We're optimistic and have our fingers crossed you're going to show up and do your job," Paul told about 200 people in Mason City, the final stop of the day.
Paul railed as equally against Democrat-backed programs as he did against typically Republican priorities such as the Patriot Act.
Paul has steadily gained ground in Iowa in the last two months. And while he narrowly trailed only Romney a series of polls published last week, support had leveled off in the wake of sharp attack over his opposition to preventing an Iranian nuclear weapon with a military strike.
It did not dissuade him from repeating in Davenport and Cedar Rapids a line that brought loud cheers in Des Moines. "Just listen to some of the candidates. They are willing to start bombing Iran right now. One thing is for certain, this country does not need another war," Paul told the crowd in Davenport, prompting loud cheers.
And while Paul himself steered clear of criticizing his rivals, his son Rand repeatedly struck at Santorum, who has supported foreign aid spending, a rallying point of opposition for fiscal hawks including tea party supporters.
"You've got so-called GOP candidates for president traipsing round Iowa who have voted for foreign aid," Rand Paul said to a cheering crowd of more than 300 in Cedar Rapids.
The campaign was preparing an automated call criticizing Santorum's support for foreign aid and other parts of the former senator's fiscal record.
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