(CNN) -- With six days to go until the New Hampshire primary, there are ties in poll results for the top candidates in both parties.
Sen. John McCain, left, has come back to tie ex-Gov. Mitt Romney in a New Hampshire poll.
With roughly a quarter of those polled in both parties saying they won't make up their mind until the election, both the Democratic and Republican presidential nomination races are up for grabs.
Sen. John McCain of Arizona, whose campaign was languishing six months ago, and former Massachusetts Gov. Mitt Romney are now tied for first place, with each grabbing the support of 29 percent of likely New Hampshire Republican primary voters, the CNN/WMUR poll conducted by the University of New Hampshire found. Watch an examination of Romney's attack ads »
Former New York Mayor Rudy Giuliani is at 12 percent with former Arkansas Gov. Mike Huckabee at 10 percent. The remaining Republican White House hopefuls for the 2008 campaign are in single digits.
"It's the McCain comeback. His New Hampshire support dropped abruptly over the summer, when his campaign nearly ran out of money. But he's made steady gains since then," CNN senior political analyst Bill Schneider said.
McCain was tied with Giuliani for the lead in New Hampshire in February and March, but by July he had dropped into fourth place with just 12 percent. Much of the political world left McCain for dead after cash problems forced him to cut his staff.
McCain's share of the vote has grown steadily through December, and the poll suggests it has come at the expense of Giuliani.
"For the first time, GOP primary voters see McCain and not Giuliani as best able to handle terrorism, and a whopping 53 percent feel he could do the best job with the war in Iraq, which is up from 38 percent in mid-December," CNN polling director Keating Holland said.
"Romney has a major advantage on the economy and illegal immigration. When it comes to the personal qualities of the two men, McCain has taken the lead on experience and is seen as more honest. Republican primary voters view Romney as more likable and the two are tied on values," Holland added.
When it comes to electability, Romney has the advantage.
"New Hampshire Republicans think Romney has the best chance of beating the Democrat in November," Schneider said.
The Democratic race in New Hampshire has tightened up, too. Sen. Hillary Clinton of New York has a 4-point lead over Sen. Barack Obama of Illinois, 34 percent to 30 percent, among likely Democratic primary voters. But if you take into account the survey's sampling error of plus or minus 5 percentage points, it's a statistical dead heat.
Former North Carolina Sen. John Edwards is at 17 percent in the poll, with the remaining Democratic presidential candidates in single digits.
Clinton has an advantage on the economy, the war in Iraq and especially health care. She is also seen as the most experienced and most electable Democratic candidate, but show scores low on honesty. Obama is far and away considered the most likable person in the race.
Obama has also scored one public relations victory -- he is now seen as the candidate of change. Back in September, a plurality thought Clinton was best able to bring change to the country; now Obama has the edge on that measure.
It appears many Granite State residents are waiting until next Tuesday to make their decision. Twenty-nine percent of likely Republican primary voters and 24 percent of likely Democratic Party voters say they won't decide whom to vote for until election day.
There's also the Iowa factor. The caucuses, which kick off the presidential primary season, are Thursday, five days before the vote in New Hampshire. Watch how candidates are doing in key Iowa contest »
A CNN/Opinion Research Corp. poll released Tuesday showed that contest too close to call, too. Clinton and Obama are within a few points on the Democratic side and Romney and Huckabee are atop the Republican field.
"Even though many Granite State voters won't admit it, the Iowa caucuses usually affect the playing field in New Hampshire," Holland said. "It's worth noting that a strong showing by any candidate in the Iowa caucuses, even those in single digits, could change the race."
"When it's this close in both parties, what happens five days earlier in Iowa is bound to affect the New Hampshire result. If Romney or Clinton loses Iowa, they may go down in New Hampshire as well," Schneider added.
The poll was conducted from December 27 to December 30. Pollsters interviewed 521 likely Democratic primary voters and 439 likely Republican primary voters by phone. E-mail to a friend
All About U.S. Presidential Election