Kerry led Howard Dean 24.4% to 23.1% in the three-day tracking poll, with Richard Gephardt at 18.8% and John Edwards at 18.4% in the tightest Iowa campaign in history.
Tonight’s caucus is the first test in the Democratic race to pick a challenger to President Bush, and Dean and Gephardt had battled for the top spot in polls in the state for months.
But Kerry, a Massachusetts senator, and Edwards, a North Carolina senator, roared in to join them over the last week as Iowa Democrats took a fresh look at the candidates and whether they could beat Bush in November.
“Kerry continues to poll strong. Dean seems to have bottomed out and move almost back to where he was,” said pollster John Zogby. “There are fewer doubts about Dean’s ability to defeat Bush, a factor that has hurt him much of this week.”
Kerry gained nearly two percentage points in the latest poll, with Dean picking up one point. Gephardt and Edwards remained relatively motionless, with Gephardt falling slightly and Edwards picking up half of a percentage point.
A tracking poll combines the results of three consecutive nights of polling, then drops the last night’s results each time a new night is added. It allows pollsters to record shifts in voter sentiment as they happen.
The poll found 10% of likely caucus-goers were still undecided, leaving plenty of opportunity for more momentum swings in the last 24 hours of the race.
The tracking poll of 502 likely caucus-goers was taken Thursday through Saturday and will continue for one more day, with the last poll published today. It has a margin of error of 4.5 percentage points.
A Des Moines Register poll published Sunday showed Kerry with a slight lead on Edwards, 26%-23% with Dean at 20% and Gephardt at 18%.
Zogby said about two-thirds of the backers for all four of the candidates described their support as “very strong.” The winner, as always in Iowa, is likely to be the candidate who is most successful at getting his supporters to the caucuses.
Retired general Wesley Clark was at 3%, Ohio Representative Dennis Kucinich at 2%, Connecticut senator Joseph Lieberman at 1% and former civil rights activist Al Sharpton at less than 1%.