NEW HAMPTON, Iowa – Hillary Rodham Clinton has taken the lead among Democratic presidential candidates in an Iowa poll, an encouraging sign of progress toward overcoming a big hurdle in the race.

Although the New York senator is the clear front-runner in national surveys, Iowa has remained an elusive prize. She has been in a tight race with John Edwards and Barack Obama in the state that begins the primary campaign voting in three months.

Clinton was supported by 29 percent of the 399 respondents to the poll conducted Oct. 1-3, compared with 21 percent in May.

Edwards and Obama are not far behind, ensuring that all three campaigns will continue their intense efforts in Iowa, which leads off voting in the 2008 primary contests.

“I’m doing everything I can to earn the support of Iowans,” Clinton said during a stop in New Hampton.

“I pay absolutely no attention to what any poll says or what any pundit on TV says,” the former first lady said.

While Clinton visited small towns in eastern Iowa, Edwards was in the midst of a four-day tour of the state that included stops in 17 counties. The new poll showed his support falling from 29 percent, good enough for first place in May, to 23 percent. That is a statistical tie with Obama’s 22 percent.

The poll has a margin of error of 4.9 percentage points.

Edwards told reporters in Davenport that he sees it as a close three-way race, with his two chief rivals rising recently because “they spend millions of dollars on television advertising.”

“But, I think it’s much more important to Iowa caucus-goers to see you in the flesh – see you stand before them, look them in the eye and answer their hard questions,” the former North Carolina senator said.

Clinton got one of those hard questions in New Hampton, and it led to a heated exchange.

Randall Rolph of Nashua challenged her for voting last month to designate Iran’s Islamic Revolutionary Guard Corps a terrorist organization. Some Democrats said they feared that such a designation could be interpreted as a congressional authorization of military force in Iran.

Rolph compared Clinton’s vote on the Iran measure with her vote to authorize war in Iraq. “It appears you haven’t learned from your past mistakes,” he said.

Clinton responded that his interpretation was wrong and suggested that someone put him up to asking the question. The man said he did his own research and was offended that she would accuse him of getting it elsewhere. She apologized but insisted he must be looking at the wrong version of the bill.

Associated Press writer Amy Lorentzen to this report.