WASHINGTON (CNN) -- Just two weeks until the Iowa caucuses, the Democratic presidential candidates appear to be in a dead heat in the Hawkeye State, according to a new CNN/Opinion Research Corp. poll.

Thirty percent of likely Iowa Democratic caucus-goers support Sen. Hillary Clinton of New York as the nominee, with Sen. Barack Obama of Illinois at 28 percent and former Sen. John Edwards of North Carolina at 26 percent, according to the poll, released Thursday morning.

With the poll's sampling error at plus or minus 4 percentage points, it's a virtual tie for the top spot in Iowa, the first state to vote in the race for the White House.

New Mexico Gov. Bill Richardson is at 7 percent, with the remaining Democratic candidates all in the lower single digits.

On the Republican side, 33 percent of likely GOP caucus-goers support former Arkansas Gov. Mike Huckabee as the nominee.

Former Massachusetts Gov. Mitt Romney comes in second place at 25 percent, followed by former New York City Mayor Rudy Giuliani with 11 percent. See which issues are fueling Iowans' picks »

Sen. John McCain of Arizona and former Sen. Fred Thompson of Tennessee are tied at 9 percent, Rep. Ron Paul of Texas at 6 percent, with the rest of the Republican field in the lower single digits. Watch how different issues point to different candidates »

The margin of error for Republican caucus voters is plus or minus 5 percentage points.

There are only 14 days left until Iowans head out to caucus, but the survey suggests that many voters have yet to make up their minds. One in three likely Democratic caucus-goers say they're still trying to decide whom to support. That number's even higher among likely Republican caucus-goers, with 40 percent still undecided on their choice for the nominee.

CNN Polling Director Keating Holland warned that "all these figures should be treated with extra caution, because it is extraordinarily difficult for polls to accurately assess who will attend the caucuses, and Iowans are notorious for making their minds up late in the game."

The survey indicates that Iraq is still the top issue for Democrats, with one in three likely Democratic caucus-goers saying the war is the most important issue in their choice for president. Health care follows at 27 percent with the economy 1 point back.

"Clinton is seen as the candidate who is best able to handle the economy, Iraq, and health care -- the top three issues of concern to Democratic caucus-goers -- with her biggest advantage on health care," Holland said.

The economy appears to be the most pressing issue for Republicans, with one in four likely Republican caucus-goers saying the economy is the most important issue in their choice. That's followed by illegal immigration at 20 percent, abortion at 18 percent, terrorism at 17 percent and the Iraq War at 12 percent.

It appears Iowa Republicans think Romney would do the best job among the GOP White House hopefuls in handling the economy, with 34 percent of likely GOP caucus-goers choosing Romney, 11 points ahead of Huckabee.

"Although Huckabee is the favorite candidate of likely GOP caucus-goers, they admit that other candidates would do a better job on nearly every issue tested. For some, such as terrorism, immigration and Iraq, he finishes in third place," Holland said.

"What's driving the Huckaboom? Abortion. It's the only issue tested on which Huckabee ranks first, indicating that even though he is not a single-issue candidate, he may have single-issue appeal."

It appears the Huckabee vote is the born-again vote, with the poll suggesting his support among Iowans who say they are born-again or evangelical Christians is nearly 30 points higher than among nonevangelicals.

Huckabee served as a Baptist pastor before entering politics. Romney has a 10 point edge among nonevangelical voters.

"There is also a surprising gender gap among likely GOP caucus-goers," says Holland. The poll indicates women prefer Huckabee over Romney by a 40 percent to 18 percent margin. Among men, it's Romney 30 percent and Huckabee 28 percent.

On the Democratic side, Clinton is the favorite of women, older voters, liberals and those making less than $50,000 a year. Obama has an edge among moderates and younger voters; Edwards does best in union households and among married voters.

The poll surveyed 543 Iowa residents who say they are likely to vote in the Democratic caucuses, and 359 who say they are likely to vote in the Republican caucuses. Interviews were conducted by telephone December 14 to 18. E-mail to a friend

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