The latest survey of Iowa Democrats by ABC News and the Washington Post has Obama in the lead with 30 percent, followed by Clinton at 26 percent. Former North Carolina Senator John Edwards is running third with 22 percent, followed by New Mexico Governor Bill Richardson with 11 percent.
Clinton continues to hold a wide lead over Obama in national surveys.
The latest Iowa poll indicates Obama is gaining strength and comes in the wake of the latest Democratic debate in which Obama questioned Clinton on the issues of trust and credibility.
"What the American people are looking for right now is straight answers to tough questions and that is not what we have seen out of Senator Clinton," said Obama.
Clinton responded that she has become the subject of attacks from her Democratic rivals for a simple reason.
"People are not attacking me because I am a woman," she said. "They are attacking me because I am ahead."
The latest survey indicates those who are most interested in a candidate with strength and experience prefer Clinton, while those who want change are drawn to Obama.
Iowa begins the presidential nominating process with its presidential caucuses for both parties on January 3.
University of Virginia political analyst Larry Sabato says Iowa represents the best chance for Clinton's Democratic rivals to narrow her lead in the national polls.
"I think it is entirely possible that Clinton is going to be given a good run for her money in Iowa," said Sabato. "It is conceivable that she will lose Iowa, and if she does lose Iowa, then it becomes a real contest for the Democratic nomination.
Professor Sabato is the guest on VOA's Talk to America Web chat.
Less than a week after Iowa, the candidates are scheduled to compete in the nation's first presidential primary in New Hampshire.
New Hampshire Secretary of State Bill Gardner told the C-SPAN public affairs network that voters there have a tradition of not committing to one candidate until the very last minute.
"Most people in New Hampshire, most voters, are going to make up their minds at the very end because there is no need to be for someone to the exclusion of everyone else right now," said Gardner.
There is plenty of uncertainty in the battle for the Republican Party's presidential nomination as well. Former New York City Mayor Rudy Giuliani leads the national polls among Republican voters. But surveys in the early voting states of Iowa and New Hampshire indicate former Massachusetts Governor Mitt Romney is currently leading the Republican field in both states.