Two opinion polls show the Democratic race in next week's Iowa caucuses too close to call, while Republican Mitt Romney appears to have regained some ground over rival Mike Huckabee.
A poll by MSNBC/McClatchy shows the Democratic race remains a virtual three-way tie between John Edwards, Hillary Clinton and Barack Obama.
Where Edwards previously had lagged slightly behind Clinton and Obama, the poll showed him at 24 percent, compared with Clinton at 23 percent and Obama at 22 percent.
While that difference is within the poll's margin of error, it could indicate late momentum for the former North Carolina senator and 2004 Democratic presidential running mate.
Among Republicans, the poll shows Mitt Romney regaining a slight lead over Mike Huckabee — 27 percent to 24 percent — although the difference is within the poll's margin of error, making the race a virtual tie.
In the last month, Huckabee had surged from the GOP's second tier to the front of the pack in Iowa, overtaking Romney, who long had held the lead there. But the former Arkansas governor's lead appears to have evaporated — he's fallen 8 percentage points since a poll taken Dec. 3-6.
The poll also found, however, that one in five Iowa Democrats and one in three Iowa Republicans said they could still change their minds before the caucuses on Thursday — the first big test in the state-by-state battle to choose candidates for the November presidential election.
The telephone survey was taken Dec. 26-28 by Mason-Dixon Polling & Research. The poll of 400 Democratic and 400 Republican likely caucus-goers has a margin of error of plus or minus 5 percentage points for each party.
Results from second poll
A Reuters/C-Span/Zogby poll showed Clinton ahead of Obama by 31 percent to 27 percent, with Edwards a close third at 24 percent.
In that same poll, Huckabee held a statistically insignificant one-point edge over Romney, 29 percent to 28 percent. Arizona Sen. John McCain was a distant third with 11 percent.
The poll of 934 likely Democratic caucus-goers and 867 likely Republican caucus-goers was taken Wednesday through Saturday and has a margin of error of 3.3 percentage points for the Democrats and 3.4 percentage points for the Republicans.
"We have two very tight races that are too close to call," said pollster John Zogby. "But there is a lot of potential for things to change here."
Clinton, Obama and Edwards have battled for the Democratic lead for months in Iowa, where a win can generate huge momentum for later contests. The Reuters/C-Span/Zogby poll showed Clinton, who would be the first woman in the White House, narrowly leading Obama among women voters and ahead among older voters, who are the most likely to participate.
Obama, who would be the first black president, held a big lead among younger voters, whose participation is more unpredictable.
The poll found Clinton's supporters were the most dedicated, with 76 percent saying their support was "very" strong, compared to 65 percent for Edwards and 56 percent for Obama.
Under Iowa's arcane caucus rules, candidates must receive support from 15 percent of the participants in each precinct to be viable. If not, their supporters can switch to other candidates.
Edwards was the most popular second choice with 30 percent, while Obama had 25 percent and Clinton only 12 percent.
Among Republicans, where Huckabee's recent surge to the top of many Iowa polls has been fueled by support among religious conservatives, the former Baptist preacher led among those who said they were "very" conservative, and born-again Christians.
About half of Romney and Huckabee's supporters described their backing as "very" strong.
The race for third among Republicans is wide open between McCain, Fred Thompson, Rudy Giuliani and Ron Paul, all of whom could take some solace from a strong finish and hope to generate momentum for the next contests.
McCain and Giuliani have barely competed in Iowa, preferring to focus on New Hampshire and a big round of contests on Feb. 5, respectively. Thompson largely ignored the state until launching a final push here in the week before Christmas.