| COLUMBIA, South Carolina
COLUMBIA, South Carolina Republican Mitt Romney climbed into a tie with John McCain three days before a critical presidential primary in Florida, according to a Reuters/C-SPAN/Zogby poll released on Sunday.
Romney, the former Massachusetts governor, wiped out a 3-point McCain advantage overnight to pull into a deadlock with the Arizona senator at 30 percent. The margin of error in the poll is 3.4 percentage points.
Romney enjoys big leads among Republican voters who describe themselves as conservative or very conservative, while McCain has an edge among Florida moderates ahead of Tuesday's primary.
They also were tied among most key demographic groups in the state. Romney held a slight edge among seniors, who make up more than a third of the sample in Florida, and among voters under 30.
Former Arkansas Gov. Mike Huckabee gained 4 points overnight to register 14 percent and move past former New York Mayor Rudy Giuliani, who continued his downward slide by losing two points to 13 percent.
Texas Rep. Ron Paul was at 3 percent and about 9 percent of likely Republican primary voters in Florida were undecided.
"This is a two-man race. It's all coming down to McCain versus Romney," said pollster John Zogby.
"Romney is ticking up a bit and he's getting strong support from conservatives," he said. "It's just going to be a battle from here on in."
The two candidates split last week's nominating contests as Republicans battle for the right to represent the party in November's presidential election. McCain won in South Carolina and Romney won in Michigan and Nevada.
The winner in Florida will gain valuable momentum heading into the February 5 "Super Tuesday" voting, when 22 states will have Republican nominating contests.
The rolling poll was taken before McCain won the endorsement of popular Florida Gov. Charlie Crist on Saturday. It also was before the issue of Iraq flared when McCain accused Romney of backing a set withdrawal of U.S. troops -- a charge Romney angrily denied.
Giuliani, the one-time leader in national polls whose standing has plummeted after he pulled out of the early voting states to focus on Florida, continued a slide that has cast doubt on the future of his campaign.
"Giuliani is becoming less and less of a factor here," Zogby said.
The poll in Florida showed the economy was the top issue among likely voters, at 39 percent. The war on terrorism ranked second at 14 percent, ahead of the war in Iraq at 12 percent.
Democrats also will hold a primary in Florida, but because of a dispute between the state and national parties over the date of the contest none of the presidential contenders have campaigned there and no delegates to the national nominating convention are at stake.
The rolling poll Florida poll of 814 likely Republican voters was taken Thursday through Saturday.
In a rolling poll, the most recent day's results are added while the oldest day's results are dropped in order to track changing momentum.
(Editing by Sandra Maler)
(For more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/)